Task - Collections - Finding Duplicates Using equals() #46

akash-coded · 2022-03-04T08:00:43Z

akash-coded
Mar 4, 2022
Maintainer

Duplicate Books in a Library

Define a class called Book.
The skeleton of the Book class is given below:

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    // parameterised constructor

    // override toString()

   // override hashCode()

   // override equals()
}

Write the implementation for hashCode() and equals() manually. (Decide which fields are important)

In the driver class, create four instances of Book class as follows:

Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);

Add the book objects to an ArrayList called library.

Print the important details of duplicate books in the list, along with a count of the number of duplicate books.

Print the details of the non-duplicate books with the highest quantity.

Expected Output:

No. of duplicate books = 1
// important fields of b1 (or b4)

// details of b2

Gaurav-Joshi-31 · 2022-03-04T08:28:02Z

Gaurav-Joshi-31
Mar 4, 2022

BOOK CLASS---

public class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

DRIVER CLASS---

import java.util.ArrayList;
import java.util.List;

public class BookDriver {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> list = new ArrayList<>();
        list.add(b1);
        list.add(b2);
        list.add(b3);
        list.add(b4);
        List<Book> duplicate = new ArrayList<>();
        for (int i = 0; i < list.size() - 1; i++) {
            for (int j = i + 1; j < list.size(); j++) {
                if (list.get(j).equals(list.get(i))) {
                    duplicate.add(list.get(j));
                    list.remove(j);
                    list.remove(i);

                }
            }
        }

        System.out.println("No of duplicate books  " + duplicate.size());
        duplicate.forEach(System.out::println);

        int maxIndex = 0;
        for (int i = 1; i < list.size(); i++) {
            if (list.get(i).quantity > list.get(maxIndex).quantity)
                maxIndex = i;
        }
        System.out.println(list.get(maxIndex));

    }
}

0 replies

Sarfinaa · 2022-03-04T08:35:37Z

Sarfinaa
Mar 4, 2022

package week_4.collections;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public int hashCode() {
        int prime = 31;
        int result = 1;
        result = prime * result + (name == null ? 0 : name.hashCode()) + ((author == null ? 0 : author.hashCode()))
                + id;
        return result;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (id != other.id)
            return false;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

public class Books {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> library = new ArrayList<>(Arrays.asList(b1, b2, b3, b4));
        Set<Book> set = new HashSet<>();

        for (int i = 0; i < library.size(); i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(i).equals(library.get(j))) {
                    set.add(library.get(i));
                }
            }
        }
        System.out.println(String.format("No. of duplicate books = %d", set.size()));
        for (Book book : set) {
            System.out.println(book);
        }
        Book maxQuantity = null;
        int max = Integer.MIN_VALUE;
        for (Book book : library) {
            if (!set.contains(book)) {
                if (max < book.quantity) {
                    maxQuantity = book;
                    max = book.quantity;
                }
            }
        }
        System.out.println(maxQuantity);
    }
}

0 replies

Khyati-tripathi · 2022-03-04T09:00:19Z

Khyati-tripathi
Mar 4, 2022

package CollectionModule;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

    

}

public class Employee {
    public static void main(String[] args) {

        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);
        Set<Book> duplicate = new HashSet();

        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i)))
                    duplicate.add(library.get(j));
            }
        }

        List<Book> nonDuplicate = new ArrayList<>(library);
        nonDuplicate.removeAll(duplicate);

        System.out.println("No of duplicate books: " + duplicate.size());
        duplicate.forEach(System.out::println);
        int high = 0;
        for (int i = 0; i < nonDuplicate.size(); i++) {
            if (nonDuplicate.get(i).quantity > nonDuplicate.get(high).quantity)
                high = i;
        }
        System.out.println("Highest quantity: ");
        System.out.println(nonDuplicate.get(high));

    }
}

0 replies

preeti-max · 2022-03-04T09:06:07Z

preeti-max
Mar 4, 2022

package Collections;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

}

public class BookDriver {

    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> library = new ArrayList<>();
        Set<Book> set = new HashSet<>();

        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);
        for (int i = 0; i < library.size() - 1; i++) {
            Book a = library.get(i);
            for (int j = i + 1; j < library.size(); j++) {
                if (a.equals(library.get(j))) {
                    set.add(a);
                }

            }
        }
        System.out.println("NO of duplicates found: " + set.size());
        set.forEach(b -> System.out.println(
                "Duplicate books: +Book id: " + b.id + " Book name: " + b.name + " Book author:" + b.author));

        Book maxBook = null;
        ArrayList<Book> library2 = new ArrayList<>(library);
        library2.removeAll(set);
         int max = Integer.MIN_VALUE;
        for (Book b : library2) {

            if (b.quantity > max) {
                max = b.quantity;
                maxBook = b;

            }

        }
        System.out.println("Details of book with max quantity");
        System.out.println(maxBook);

    }

}

0 replies

ratnadeepikavuddagiri · 2022-03-04T09:08:04Z

ratnadeepikavuddagiri
Mar 4, 2022

package JavaCollections;

import java.util.ArrayList;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;
    
    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [id=" + id + ", name=" + name + ", author=" + author + "]";
    }

    
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (this.getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (this.author == null) {
            if (other.author != null)
                return false;
        } else if (!this.author.equals(other.author))
            return false;
        if (this.id != other.id)
            return false;
        if (this.name == null) {
            if (other.name != null)
                return false;
        } else if (!this.name.equals(other.name))
            return false;
        return true;
    }

}
public class BookDriver {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        ArrayList<Book> bookList = new ArrayList<>();
        bookList.add(b1);
        bookList.add(b2);
        bookList.add(b3);
        bookList.add(b4);
        int dupCount=0;
        ArrayList<Book> duplicateList = new ArrayList<>();
        for(int i=0; i<bookList.size(); i++) {
            for(int j=i+1; j<bookList.size(); j++){
                if(bookList.get(j).equals(bookList.get(i))){
                    dupCount++;
                    duplicateList.add(bookList.get(j));
                    bookList.remove(j);
                    bookList.remove(i);
                }
            }
        }
        System.out.println("No. of duplicate books = "+dupCount);
        for(int i=0;i<duplicateList.size(); i++){
            System.out.println(duplicateList.get(i));
        }
        int maxQuantity = 0;
        Book temp=null;
        for(int i=0;i<bookList.size(); i++){
            if(bookList.get(i).quantity>maxQuantity){
                    maxQuantity = bookList.get(i).quantity;
                    temp = bookList.get(i);
            }
        }
        System.out.println(temp);
    }
}

0 replies

rakeshGit419 · 2022-03-04T09:21:43Z

rakeshGit419
Mar 4, 2022

import java.util.*;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;
    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }
    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (obj == null) return false;
        if (getClass() != obj.getClass()) return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null) return false;
        } else if (!author.equals(other.author)) return false;
        if (id != other.id) return false;
        if (name == null) {
            if (other.name != null) return false;
        } else if (!name.equals(other.name)) return false;
        return true;
    }

}


public class BookDriver {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> library = Arrays.asList(b1,b2,b3,b4);
        library.forEach(System.out::println);
        Set<Book> set = new HashSet<>();
        Book b5 = null;
        int maxQuant = 0;
        for(int i=0;i<library.size();i++){
            for(int j=i+1;j<library.size();j++){
                if(library.get(i).equals(library.get(j))){
                    set.add(library.get(i));
                }
            }
        }
        for(Book b : library){
            if(!set.contains(b)){
                if(b.quantity > maxQuant){
                    maxQuant = b.quantity;
                    b5 = b;
                }
            }
        }
        System.out.println("No. of duplicate books = "+set.size());
        set.forEach(System.out::println);
        System.out.println(b5);

    }
}

0 replies

KaminiJha · 2022-03-04T09:28:47Z

KaminiJha
Mar 4, 2022

package Collections;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    // parameterised constructor
    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    // override equals()
    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        } else if (other == null) {
            return false;
        } else if (this.getClass() != other.getClass())
            return false;
        Book obj = (Book) other;
        if (id != obj.id) {
            return false;
        } else {
            return this.name.equals(obj.name) && this.author.equals(obj.author)
        }
    }

    // override hashCode()
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    // override toString()
    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

}

public class BooksDriver {
    public static void main(String[] args) {

        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        // Add the book objects to an ArrayList called library.
        List<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        // Print the important details of duplicate books in the list, along with a
        // count of the number of duplicate books.
        List<Book> dups = new ArrayList<>();
        printDuplicatesDetail(library, dups);
        // // Print the details of the non-duplicate books with the highest quantity.
        printHighestQuantityBook(library, dups);
    }

    public static void printDuplicatesDetail(List<Book> library, List<Book> dups) {
        System.out.println("Priniting duplicate books");
        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(i).equals(library.get(j))) {
                    if (!dups.contains(library.get(i))) {
                        dups.add(library.get(i));
                    }
                }
            }
        }
        dups.forEach(System.out::println);
    }

    public static void printHighestQuantityBook(List<Book> library, List<Book> dups) {
        Book maxQuantityBook = null;
        int maxQuantity = Integer.MIN_VALUE;
        for (int i = 0; i < library.size(); i++) {
            Book b = library.get(i);
            if (!dups.contains(b)) {
                if (b.quantity > maxQuantity) {
                    maxQuantity = b.quantity;
                    maxQuantityBook = b;
                }
            }
        }
        System.out.println("Book with max quantity and non duplicate -->");
        System.out.println(maxQuantityBook);
    }
}

0 replies

Amrit-Raj22 · 2022-03-04T09:29:08Z

Amrit-Raj22
Mar 4, 2022

package week4.day1.day5;

import java.util.ArrayList;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    String imp() {
        return "id=" + this.id + ", name=" + this.name + ", auther=" + this.author;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        else if (!name.equals(other.name))
            return false;
        return true;
    }

    // override hashCode()

    // override equals()
}

public class DuplicateBook {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        ArrayList<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        int duplicateBook = 0;
        ArrayList<Book> duplicateList = new ArrayList<>();
        for (int i = 0; i < library.size(); i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i))) {
                    duplicateBook++;
                    duplicateList.add(library.get(j));
                    library.remove(j);
                    library.remove(i);
                }
            }
        }
        System.out.println("duplicate count:" + duplicateBook);
        for (Book b : duplicateList) {
            System.out.println("duplicate book Imp.detail:" + b.imp());
        }
        int max_q = Integer.MIN_VALUE;
        int i = 0;
        for (; i < library.size(); i++) {
            if (library.get(i).quantity > max_q) {
                max_q = library.get(i).quantity;
            }
        }
        System.out.println("max quantity:(non duplicate)" + library.get(i - 1));

    }

}

0 replies

RohitNaikade1 · 2022-03-04T09:29:44Z

RohitNaikade1
Mar 4, 2022

import java.util.*;
class Book{
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher,int quantity){
        this.id=id;
        this.name=name;
        this.author=author;
        this.publisher=publisher;
        this.quantity=quantity;
    }

    @Override
    public String toString() {
        return "Book [id=" + id + ", name=" + name + ", author=" + author +  "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Book other = (Book) obj;
    if (author == null) {
        if (other.author != null)
            return false;
    } else if (!author.equals(other.author))
        return false;
    if (id != other.id)
        return false;
    if (name == null) {
        if (other.name != null)
            return false;
    } else if (!name.equals(other.name))
        return false;
    return true;
    }

    
}

public class FindDuplicates {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        ArrayList<Book> bookstore = new ArrayList<>();
        bookstore.add(b1);
        bookstore.add(b2);
        bookstore.add(b3);
        bookstore.add(b4);

        HashSet<Book> duplicates = new HashSet<>();

        for(int i=0;i<bookstore.size()-1;i++){
            for(int j=i+1;j<bookstore.size();j++){
                if(bookstore.get(j).equals(bookstore.get(i))){
                    duplicates.add(bookstore.get(i));
                }
            }
        }

        System.out.println("Number of Duplicates: " + duplicates.size());
        duplicates.forEach(System.out::println);

        int maxIndex=0,maxQty=0;

        for(int i=1;i<bookstore.size();i++){
            if(duplicates.contains(bookstore.get(i))){
                continue;
            }
            if(bookstore.get(i).quantity > maxQty){
                maxIndex=i;
                maxQty=bookstore.get(i).quantity;
            }
        }

        System.out.println("Max quantity Book:");
        System.out.println(bookstore.get(maxIndex));
    }
}

0 replies

Mrafe · 2022-03-04T09:34:01Z

Mrafe
Mar 4, 2022

package week5.friday;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

}

public class BookDriver {

    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> library = new ArrayList<>();
        Set<Book> set = new HashSet<>();

        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);
        for (int i = 0; i < library.size() - 1; i++) {
            Book a = library.get(i);
            for (int j = i + 1; j < library.size(); j++) {
                if (a.equals(library.get(j))) {
                    set.add(a);
                }

            }
        }
        System.out.println("No. of duplicates found: " + set.size());
        set.forEach(System.out::println);

        Book maxBook = null;

        library.removeAll(set);
        int max = Integer.MIN_VALUE;
        for (Book b : library) {

            if (b.quantity > max) {
                max = b.quantity;
                maxBook = b;

            }

        }
        System.out.println("Book with Max quantity \n"+maxBook);

    }

}

0 replies

Batchusatyasri · 2022-03-04T09:36:37Z

Batchusatyasri
Mar 4, 2022

package Collectiontask;

import java.util.*;

class Book {
int id;
String name;
String author;
String publisher;
int quantity;
Book(int id, String name, String author, String publisher, int quantity) {
    this.id = id;
    this.name = name;
    this.author = author;
    this.publisher = publisher;
    this.quantity = quantity;
}

@Override
public String toString() {
    return "Book id: " + id + ", Bookname: " + name + ", Bookauthor: " + author + ", Bookpublisher: " + publisher
            + ", Bookquantity: " + quantity;
}

int count = 0;

public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((author == null) ? 0 : author.hashCode());
    result = prime * result + ((name == null) ? 0 : name.hashCode());
    return result;
}

public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (this.getClass() != obj.getClass())
        return false;
    Book other = (Book) obj;
    if (this.author == null) {
        if (other.author != null)
            return false;
    } else if (!this.author.equals(other.author))
        return false;
    if (this.id != other.id)
        return false;
    if (this.name == null) {
        if (other.name != null)
            return false;
    } else if (!this.name.equals(other.name))
        return false;
    return true;
}
}

public class Books {
public static void main(String[] args) {
int count = 0;
Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
ArrayList library = new ArrayList<>();
library.add(b1);
library.add(b2);
library.add(b3);
library.add(b4);
ArrayList dup = new ArrayList<>();
for (int i = 0; i < library.size() - 1; i++) {
for (int j = i + 1; j < library.size(); j++) {
if (library.get(j).equals(library.get(i))) {
count++;
dup.add(library.get(j));
library.remove(j);
library.remove(i);
}
}
}
System.out.println("No. of duplicate books = " + count);
for (int i = 0; i < dup.size(); i++) {
System.out.println(dup.get(i));
}
int k = 0;
Book temp = null;
for (int i = 0; i < library.size(); i++) {
if (library.get(i).quantity > k) {
k = library.get(i).quantity;
temp = library.get(i);
}
}
System.out.println(temp);
}
}

0 replies

deepak775035 · 2022-03-04T09:37:30Z

deepak775035
Mar 4, 2022

package session20;

import java.util.ArrayList;

class Book {

    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

}

public class DuplicateBookDriver {
    public static void main(String[] args) {

        ArrayList<Book> library = new ArrayList<>();

        library.add(new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8));
        library.add(new Book(233, "Operating System", "Galvin", "Wiley", 6));
        library.add(new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4));
        library.add(new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11));

        for (int i = 0; i < library.size(); i++) {

            Book currentBook = library.get(i);
            int count = 1;
            for (int j = i + 1; j < library.size(); j++) {
                if (currentBook.equals(library.get(j))) {
                    count++;
                    library.remove(j);
                }
            }

            if (count != 1) {
                System.out.println("No. of duplicate books =" + count);
                System.out.println(currentBook);
                library.remove(i);
            }
        }

        System.out.println("\n\nUnique Highest quantity:");
        Book highestQuantityBook = null;
        for (Book book : library) {
            if (highestQuantityBook == null || highestQuantityBook.quantity < book.quantity)
                highestQuantityBook = book;
        }
        System.out.println(highestQuantityBook);

    }
}

0 replies

GantaGreeshma · 2022-03-04T09:39:47Z

GantaGreeshma
Mar 4, 2022

package collection_framework;

import java.util.*;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public boolean equals(Object book) {
        if (book == null) {
            return false;
        }
        if (this == null) {
            return false;
        }
        if (getClass() != book.getClass()) {
            return false;
        }
        Book obj = (Book) book;
        if (author == null) {
            if (obj.author != null) {
                return false;
            }
        } else if (author != obj.author) {
            return false;
        }
        if (id != obj.id) {
            return false;
        }
        if (name == null) {
            if (obj.name != null) {
                return false;
            }
        } else if (name != obj.name) {
            return false;
        }
        return true;
    }

    @Override
    public int hashCode() {
        int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

}

public class DublicateBooks {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> list = new ArrayList<>();
        list.add(b1);
        list.add(b2);
        list.add(b3);
        list.add(b4);
        List<Book> dupe = new ArrayList<>();
        for (int i = 0; i < list.size() - 1; i++) {
            for (int j = i + 1; j < list.size(); j++) {
                if (list.get(j).equals(list.get(i))) {
                    dupe.add(list.get(j));
                }

            }
        }
        System.out.println("number of dublicates :" + dupe.size());
        dupe.forEach(System.out::println);
        list.removeAll(dupe);
        int max = 0;
        for (int i = 0; i < list.size(); i++) {
            if (!(dupe.contains(list.get(i)))) {
                if (list.get(i).quantity > list.get(max).quantity) {
                    max = i;
                }
            }
        }
        System.out.println(list.get(max));
    }
}

0 replies

nithin1429 · 2022-03-04T09:40:40Z

nithin1429
Mar 4, 2022

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class Book {
int id;
String name;
String author;
String publisher;
int quantity;

public Book(int id, String name, String author, String publisher, int quantity) {
    this.id = id;
    this.name = name;
    this.author = author;
    this.publisher = publisher;
    this.quantity = quantity;
}

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((author == null) ? 0 : author.hashCode());
    result = prime * result + id;
    result = prime * result + ((name == null) ? 0 : name.hashCode());
    return result;
}

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Book other = (Book) obj;
    if (author == null) {
        if (other.author != null)
            return false;
    } else if (!author.equals(other.author))
        return false;
    if (id != other.id)
        return false;
    if (name == null) {
        if (other.name != null)
            return false;
    } else if (!name.equals(other.name))
        return false;
    return true;
}

@Override
public String toString() {
    return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
            + quantity + "]";
}

}

public class BookCount {

public static void main(String[] args) {
    Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
    Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
    Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
    Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
    List<Book> library = new ArrayList<>();
    Set<Book> set = new HashSet<>();

    library.add(b1);
    library.add(b2);
    library.add(b3);
    library.add(b4);
    for (int i = 0; i < library.size() - 1; i++) {
        Book a = library.get(i);
        for (int j = i + 1; j < library.size(); j++) {
            if (a.equals(library.get(j))) {
                set.add(a);
            }

        }
    }
    System.out.println("NO of duplicates found: " + set.size());
    set.forEach(b -> System.out.println(
            "Duplicate books: +Book id: " + b.id + " Book name: " + b.name + " Book author:" + b.author));

    Book maxBook = null;

    library.removeAll(set);
    int max = Integer.MIN_VALUE;
    for (Book b : library) {

        if (b.quantity > max) {
            max = b.quantity;
            maxBook = b;

        }

    }
    System.out.println("Details of book with max quantity");
    System.out.println(maxBook);

}

}

0 replies

sruthi-15-sketch · 2022-03-04T09:42:36Z

sruthi-15-sketch
Mar 4, 2022


class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

class BookArrayList {
    public static void main(String[] args) {
        ArrayList<Book> library = new ArrayList<>();
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);
        ArrayList<Book> duplicate = new ArrayList<>();
        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i))) {
                    duplicate.add(library.get(j));
                }
            }
        }
        library.removeAll(duplicate);
        System.out.println("No of duplicate books: " + duplicate.size());
        duplicate.forEach(System.out::println);
        // library.forEach(System.out::println);
        int max_quantity = 0;
        for (int i = 0; i < library.size() - 1; i++) {
            if (library.get(i).quantity > library.get(i + 1).quantity) {
                max_quantity = i;
            }
        }
        System.out.println("Non-duplicate books with the highest quantity " + library.get(max_quantity));
    }
}```

0 replies

Shubhi27 · 2022-03-04T10:03:41Z

Shubhi27
Mar 4, 2022

package collections;

import java.util.ArrayList;
import java.util.List;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

public class BookDriver {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> book = new ArrayList<Book>();
        book.add(b1);
        book.add(b2);
        book.add(b3);
        book.add(b4);

        List<Book> mylist = new ArrayList<>();
        mylist.add(b1);
        mylist.add(b2);
        mylist.add(b3);
        mylist.add(b4);
        List<Book> duplicate = new ArrayList<>();
        for (int i = 0; i < mylist.size() - 1; i++) {
            for (int j = i + 1; j < mylist.size(); j++) {
                if (mylist.get(j).equals(mylist.get(i))) {
                    duplicate.add(mylist.get(j));
                    mylist.remove(j);
                    mylist.remove(i);

                }
            }
        }

        System.out.println("duplicate books are:  " + duplicate.size());
        duplicate.forEach(System.out::println);

        int maxQuantity = 0;
        for (int i = 1; i < mylist.size(); i++) {
            if (mylist.get(i).quantity > mylist.get(maxQuantity).quantity)
                maxQuantity = i;
        }
        System.out.println(mylist.get(maxQuantity));
    }
}

0 replies

Harshita-Joshi · 2022-03-04T10:19:12Z

Harshita-Joshi
Mar 4, 2022

package collections;

import java.util.ArrayList;
import java.util.*;

class Book{

    int id;
    String name;
    String author;
    String publisher;
    int quantity;
    
    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

   

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        
        return true;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

}

public class BookDriver {
    public static void main(String[] args) {
        
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);

        List<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        List<Book> dup = new ArrayList<>();

        for(int i=0; i<library.size()-1; i++){
            for(int j=i+1; j<library.size(); j++){
                if(library.get(j).equals(library.get(i))){
                    dup.add(library.get(j));
                    library.remove(j);
                    library.remove(i);
                }
            }
        }

        System.out.println("Found "+ dup.size()+" duplicate(s)");
        System.out.println("Duplicate details: ");
        for(int i=0; i<dup.size(); i++){
            System.out.println(dup.get(i));
        }

        int maxQuantIndex = 0;
        for(int i=1; i<library.size(); i++){
            if(library.get(i).quantity > library.get(maxQuantIndex).quantity){
                maxQuantIndex = i;
            }
        }

        System.out.println("Non duplicate book with highest quantity");
        System.out.println(library.get(maxQuantIndex));



    }
}

0 replies

ShraddhaPenshanwar · 2022-03-06T16:58:24Z

ShraddhaPenshanwar
Mar 6, 2022


public class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}
DRIVER CLASS---

import java.util.ArrayList;
import java.util.List;

public class BookDriver {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> list = new ArrayList<>();
        list.add(b1);
        list.add(b2);
        list.add(b3);
        list.add(b4);
        List<Book> duplicate = new ArrayList<>();
        for (int i = 0; i < list.size() - 1; i++) {
            for (int j = i + 1; j < list.size(); j++) {
                if (list.get(j).equals(list.get(i))) {
                    duplicate.add(list.get(j));
                    list.remove(j);
                    list.remove(i);

                }
            }
        }

        System.out.println("No of duplicate books  " + duplicate.size());
        duplicate.forEach(System.out::println);

        int maxIndex = 0;
        for (int i = 1; i < list.size(); i++) {
            if (list.get(i).quantity > list.get(maxIndex).quantity)
                maxIndex = i;
        }
        System.out.println(list.get(maxIndex));

    }
}````

0 replies

shreiyarandive · 2022-03-06T18:13:02Z

shreiyarandive
Mar 6, 2022

import java.util.*;
class Book{
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher,int quantity){
        this.id=id;
        this.name=name;
        this.author=author;
        this.publisher=publisher;
        this.quantity=quantity;
    }

    @Override
    public String toString() {
        return "Book [id=" + id + ", name=" + name + ", author=" + author +  "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Book other = (Book) obj;
    if (author == null) {
        if (other.author != null)
            return false;
    } else if (!author.equals(other.author))
        return false;
    if (id != other.id)
        return false;
    if (name == null) {
        if (other.name != null)
            return false;
    } else if (!name.equals(other.name))
        return false;
    return true;
    }

    
}

public class FindDuplicates {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        ArrayList<Book> bookstore = new ArrayList<>();
        bookstore.add(b1);
        bookstore.add(b2);
        bookstore.add(b3);
        bookstore.add(b4);

        HashSet<Book> duplicates = new HashSet<>();

        for(int i=0;i<bookstore.size()-1;i++){
            for(int j=i+1;j<bookstore.size();j++){
                if(bookstore.get(j).equals(bookstore.get(i))){
                    duplicates.add(bookstore.get(i));
                }
            }
        }

        System.out.println("Number of Duplicates: " + duplicates.size());
        duplicates.forEach(System.out::println);

        int maxIndex=0,maxQty=0;

        for(int i=1;i<bookstore.size();i++){
            if(duplicates.contains(bookstore.get(i))){
                continue;
            }
            if(bookstore.get(i).quantity > maxQty){
                maxIndex=i;
                maxQty=bookstore.get(i).quantity;
            }
        }

        System.out.println("Max quantity Book:");
        System.out.println(bookstore.get(maxIndex));
    }
}

0 replies

DivikaAgrawal · 2022-03-06T19:20:57Z

DivikaAgrawal
Mar 6, 2022

package exception_handing.Collections;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.Collections;
import java.util.List;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

}

public class Library {
    public static void main(String[] args) {

        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);

        List<Book> booklist = new ArrayList<>();
        booklist.add(b1);
        booklist.add(b2);
        booklist.add(b3);
        booklist.add(b4);

        Set<Book> duplicatebook = new HashSet<>();

        for (int i = 0; i < booklist.size(); i++) {
            for (int j = i + 1; j < booklist.size(); j++) {
                if (booklist.get(i).equals(booklist.get(j)))
                    duplicatebook.add(booklist.get(i));
            }
        }

        System.out.println("No of duplicate books =" + duplicatebook.size());
        duplicatebook.forEach(System.out::println);

        List<Book> nonduplicatebook = new ArrayList<>(booklist);
        nonduplicatebook.removeAll(duplicatebook);

        int max = 0;
        int temp = 0;
        for (int i = 0; i < nonduplicatebook.size(); i++) {
            if (nonduplicatebook.get(i).quantity > max) {
                max = nonduplicatebook.get(i).quantity;
                temp = i;
            }
        }

        System.out.println("Maximum=" + max);
        System.out.println(nonduplicatebook.get(temp));

    }
}

0 replies

Snehil6197 · 2022-03-07T08:24:32Z

Snehil6197
Mar 7, 2022

import java.util.ArrayList;
import java.util.*;

class Book {
int id;
String name;
String author;
String publisher;
int quantity;

Book(int id, String name, String author, String publisher, int qty) {
    this.id = id;
    this.name = name;
    this.author = author;
    this.publisher = publisher;
    this.quantity = qty;
}

@Override
public String toString() {
    return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
            + quantity + "]";
}

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + id;
    result = result + ((name == null) ? 0 : name.hashCode());
    result = result + ((author == null) ? 0 : author.hashCode());
    return result;
}

@Override
public boolean equals(final Object other) {
    if (this == other) {
        return true;
    }
    if (other == null) {
        return false;
    }
    Book b = (Book) other;
    if (this.id != b.id) {
        return false;
    }
    if (this.getClass() != b.getClass()) {
        return false;
    }
    if ((this.name == null && b.name == null) && (this.author == null && b.author == null)) {
        return true;
    }

    if ((this.name.equals(b.name)) && (this.author.equals(b.author))) {
        return true;
    }
    return false;
}

}

public class DuplicateBooks {
public static void main(String[] args) {
List books = new ArrayList<>();
List indx = new ArrayList<>();
Set duplicate = new HashSet<>();
List nonDuplicateBooks = new ArrayList<>();
int count = 0;
Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
Book b5 = new Book(121, "Let us C", "Yashwant Kanetkar", "snehilpub", 8);
books.add(b1);
books.add(b2);
books.add(b3);
books.add(b4);
books.add(b5);
nonDuplicateBooks.addAll(books);
for (int i = 0; i < books.size() - 1; i++) {
for (int j = i + 1; j < books.size(); j++) {
if (books.get(i).equals(books.get(j))) {
count += 1;
nonDuplicateBooks.remove(books.get(i));
nonDuplicateBooks.remove(books.get(j));
duplicate.add(books.get(i));
duplicate.add(books.get(j));
}
}
}
System.out.println("duplicate book count is : " + count);
duplicate.forEach(System.out::println);
int maxIndex = 0;
for (int i = 1; i < nonDuplicateBooks.size(); i++) {
if (nonDuplicateBooks.get(i).quantity > nonDuplicateBooks.get(maxIndex).quantity)
maxIndex = i;
}
System.out.println(nonDuplicateBooks.get(maxIndex));
}

``

0 replies

lalit-ky · 2022-03-08T05:34:09Z

lalit-ky
Mar 8, 2022

package collections;

import java.util.ArrayList;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

public class BookDriver {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        ArrayList<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        ArrayList<Book> duplicate = new ArrayList<>();
        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(i).equals(library.get(j))) {
                    duplicate.add(library.get(i));
                    library.remove(j);
                    library.remove(i);
                }
            }
        }
        System.out.println("No of duplicate books = " + duplicate.size());
        duplicate.forEach(System.out::println);

        int index = 0;
        for (int i = 1; i < library.size(); i++) {
            if (library.get(i).quantity > library.get(index).quantity) {
                index = i;
            }
        }
        System.out.println("\n" + library.get(index));
    }
}

0 replies

Prem-3 · 2022-03-08T18:37:19Z

Prem-3
Mar 8, 2022

`
import java.util.*;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class Book1 {
int id;
String name;
String author;
String publisher;
int quantity;

public Book1(int id, String name, String author, String publisher, int quantity) {
    this.id = id;
    this.name = name;
    this.author = author;
    this.publisher = publisher;
    this.quantity = quantity;
}

@Override
public String toString() {
    return "Book1 [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
            + quantity + "]";
}

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((author == null) ? 0 : author.hashCode());
    result = prime * result + id;
    result = prime * result + ((name == null) ? 0 : name.hashCode());
    result = prime * result + ((publisher == null) ? 0 : publisher.hashCode());
    result = prime * result + quantity;
    return result;
}

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Book1 other = (Book1) obj;
    if (author == null) {
        if (other.author != null)
            return false;
    } else if (!author.equals(other.author))
        return false;
    if (id != other.id)
        return false;
    if (name == null) {
        if (other.name != null)
            return false;
    } else if (!name.equals(other.name))
        return false;
    if (publisher == null) {
        if (other.publisher != null)
            return false;
    } else if (!publisher.equals(other.publisher))
        return false;
    if (quantity != other.quantity)
        return false;
    return true;
}

}

public class BookDriver {
public static void main(String[] args) {
Book1 b1 = new Book1(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
Book1 b2 = new Book1(233, "Operating System", "Galvin", "Wiley", 6);
Book1 b3 = new Book1(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
Book1 b4 = new Book1(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
List library = new ArrayList<>();
library.add(b1);
library.add(b2);
library.add(b3);
library.add(b4);
Set set = new HashSet<>();
for (int i = 0; i < library.size() - 1; i++) {
Book1 a = library.get(i);
for (int j = i + 1; j < library.size(); j++) {
if (a.equals(library.get(j))) {
set.add(a);
}

        }
    }
    System.out.println("No. of duplicates found: " + set.size());
    set.forEach(System.out::println);

    Book1 maxBook = null;

    library.removeAll(set);
    int max = Integer.MIN_VALUE;
    for (Book1 b : library) {

        if (b.quantity > max) {
            max = b.quantity;
            maxBook = b;

        }

    }
    System.out.println("Book with Max quantity \n" + maxBook);

}

}

`

0 replies

ghost · 2022-07-18T10:47:43Z

ghost
Jul 18, 2022

import java.util.*;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        result = prime * result + ((publisher == null) ? 0 : publisher.hashCode());
        result = prime * result + quantity;
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        if (publisher == null) {
            if (other.publisher != null)
                return false;
        } else if (!publisher.equals(other.publisher))
            return false;
        if (quantity != other.quantity)
            return false;
        return true;
    }

    // override toString()

    // override hashCode()

    // override equals()
}

public class Main {

    public static void main(String[] args) {

        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        List<Book> duplicate = new ArrayList<>();

        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i))) {
                    duplicate.add(library.get(j));

                }
            }
        }

        System.out.println("No of duplicate books  " + duplicate.size());
        duplicate.forEach(System.out::println);
        int maxquan = 0;
        for (int i = 0; i < library.size(); i++) {
            if (library.get(i).quantity > library.get(maxquan).quantity) {
                maxquan = i;
            }
        }
        System.out.println("");
        System.out.printf("Maximum quantity of a book is: " + library.get(maxquan));

    }

}

0 replies

gayatribabar · 2022-07-18T11:15:30Z

gayatribabar
Jul 18, 2022

import java.util.List;
import java.util.ArrayList;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    // parameterised constructor
    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

}

public class Discussion46 {
    public static void main(String[] args) {

        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);

        List<Book> Library = new ArrayList<>();
        Library.add(b1);
        Library.add(b2);
        Library.add(b3);
        Library.add(b4);

        for (int i = 0; i < Library.size(); i++) {
            for (int j = i + 1; j < Library.size(); j++) {
                if (Library.get(i).equals(Library.get(j))) {
                    System.out.println(Library.get(i) + "\n" + Library.get(j) + "\n");
                    if (Library.get(i).quantity > Library.get(j).quantity) {
                        System.out.println("Duplicate book with highest quantity: \n" + Library.get(i));
                    } else if (Library.get(i).quantity < Library.get(j).quantity) {
                        System.out.println("Duplicate book with highest quantity: \n" + Library.get(j));
                    }
                }

            }
        }

    }
}

0 replies

Coder-093 · 2022-07-19T05:02:21Z

Coder-093
Jul 19, 2022

import java.util.*;

public class task46 {
  public static void main(String[] args) {
    Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
    Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
    Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
    Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);

    ArrayList<Book> library = new ArrayList<Book>();

    library.add(b1);
    library.add(b2);
    library.add(b3);
    library.add(b4);

    ArrayList<Book> library2 = new ArrayList<Book>();

    for (int i = 0; i < library.size() - 1; i++) {
      for (int j = i + 1; j < library.size(); j++) {
        if (library.get(i).equals(library.get(j))) {
          library2.add(library.get(i));
        }
      }
    }
    System.out.println("quantity of duplicate books = " + library2.size());
    library2.forEach(System.out::println);
    System.out.println();

    int qmax = 0;
    for (int i = 0; i < library.size(); i++) {
      if (library.get(i).quantity > library.get(qmax).quantity) {
        qmax = i;
      }
    }
    System.out.println("quantity of non-duplicate books = " + qmax);
    library.forEach(System.out::println);
    System.out.println();
  }
}

class Book {
  int id;
  String name;
  String author;
  String publisher;
  int quantity;

  public Book(int id, String name, String author, String publisher, int quantity) {
    this.id = id;
    this.name = name;
    this.author = author;
    this.publisher = publisher;
    this.quantity = quantity;
  }

  @Override
  public String toString() {
    return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
        + quantity + "]";
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((author == null) ? 0 : author.hashCode());
    result = prime * result + id;
    result = prime * result + ((name == null) ? 0 : name.hashCode());
    return result;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj)
      return true;
    if (obj == null)
      return false;
    if (getClass() != obj.getClass())
      return false;
    Book other = (Book) obj;
    if (author == null) {
      if (other.author != null)
        return false;
    } else if (!author.equals(other.author))
      return false;
    if (id != other.id)
      return false;
    if (name == null) {
      if (other.name != null)
        return false;
    } else if (!name.equals(other.name))
      return false;
    return true;
  }

}

0 replies

ghost · 2022-07-19T05:43:01Z

ghost
Jul 19, 2022

import java.util.ArrayList;

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    String imp() {
        return "id=" + this.id + ", name=" + this.name + ", auther=" + this.author;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        else if (!name.equals(other.name))
            return false;
        return true;
    }
}

public class d46 {
    public static void main(String[] args) {
        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        ArrayList<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        int duplicateBook = 0;
        ArrayList<Book> duplicateList = new ArrayList<>();
        for (int i = 0; i < library.size(); i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i))) {
                    duplicateBook++;
                    duplicateList.add(library.get(j));
                    library.remove(j);
                    library.remove(i);
                }
            }
        }
        System.out.println("duplicate count:" + duplicateBook);
        for (Book b : duplicateList) {
            System.out.println("duplicate book Imp.detail:" + b.imp());
        }
        int max_q = Integer.MIN_VALUE;
        int i = 0;
        for (; i < library.size(); i++) {
            if (library.get(i).quantity > max_q) {
                max_q = library.get(i).quantity;
            }
        }
        System.out.println("max quantity:(non duplicate)" + library.get(i - 1));
    }
}

0 replies

vshvandana · 2022-07-19T06:18:52Z

vshvandana
Jul 19, 2022

import java.util.ArrayList;
import java.util.List;

class book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((author == null) ? 0 : author.hashCode());
        result = prime * result + id;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        result = prime * result + ((publisher == null) ? 0 : publisher.hashCode());
        result = prime * result + quantity;
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        book other = (book) obj;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        if (publisher == null) {
            if (other.publisher != null)
                return false;
        } else if (!publisher.equals(other.publisher))
            return false;
        if (quantity != other.quantity)
            return false;
        return true;
    }

}

public class books {
    public static void main(String[] args) {
        book b1 = new book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        book b2 = new book(233, "Operating System", "Galvin", "Wiley", 6);
        book b3 = new book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        book b4 = new book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
        List<book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);
        List<book> duplicate = new ArrayList<>();
        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i))) {
                    duplicate.add(library.get(j));
                    library.remove(j);
                    library.remove(i);

                }
            }
        }

        System.out.println("No of duplicate books  " + duplicate.size());
        duplicate.forEach(System.out::println);

        int max = 0;
        for (int i = 1; i < library.size(); i++) {
            if (library.get(i).quantity > library.get(max).quantity)
                max = i;
        }
        System.out.println(library.get(max));

    }
}

0 replies

meghvi-raj · 2022-07-19T06:40:11Z

meghvi-raj
Jul 19, 2022

import java.util.ArrayList;
import java.util.List;

public class D46 {

    public static void main(String[] args) {

        Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
        Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
        Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
        Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);

        List<Book> library = new ArrayList<>();
        library.add(b1);
        library.add(b2);
        library.add(b3);
        library.add(b4);

        List<Book> duplicate = new ArrayList<>();

        for (int i = 0; i < library.size() - 1; i++) {
            for (int j = i + 1; j < library.size(); j++) {
                if (library.get(j).equals(library.get(i))) {
                    duplicate.add(library.get(j));
                    library.remove(j);
                    library.remove(i);

                }
            }
        }

        System.out.println("No of duplicate books  " + duplicate.size());
        duplicate.forEach(System.out::println);

        int maxIndex = 0;
        for (int i = 1; i < library.size(); i++) {
            if (library.get(i).quantity > library.get(maxIndex).quantity)
                maxIndex = i;
        }
        System.out.println("Non duplicate book of highest quantity: " + library.get(maxIndex));
    }

}

class Book {
    int id;
    String name;
    String author;
    String publisher;
    int quantity;

    public Book(int id, String name, String author, String publisher, int quantity) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.publisher = publisher;
        this.quantity = quantity;
    }

    @Override
    public int hashCode() {
        int prime = 31;
        int result = 1;
        result = prime * result + (name == null ? 0 : name.hashCode()) + ((author == null ? 0 : author.hashCode()))
                + id;
        return result;
    }

    @Override
    public String toString() {
        return "Book [author=" + author + ", id=" + id + ", name=" + name + ", publisher=" + publisher + ", quantity="
                + quantity + "]";
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (id != other.id)
            return false;
        if (author == null) {
            if (other.author != null)
                return false;
        } else if (!author.equals(other.author))
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

0 replies

NavneetBais · 2022-08-18T05:28:11Z

NavneetBais
Aug 18, 2022

Book

import java.util.Objects;

public class Book {
		int id;
	    String name;
	    String author;
	    String publisher;
	    int quantity;
		public Book(int id, String name, String author, String publisher, int quantity) {
			super();
			this.id = id;
			this.name = name;
			this.author = author;
			this.publisher = publisher;
			this.quantity = quantity;
		}
		@Override
		public String toString() {
			return "Book [id=" + id + ", name=" + name + ", author=" + author + ", publisher=" + publisher
					+ ", quantity=" + quantity + "]";
		}
		@Override
		public int hashCode() {
			int prime = 31 ;
			int result = 0 ;
			result = result * prime + id ;
			return result ;
		}
		
		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			Book obj1 =(Book) obj ;
			if(this.id != obj1.id) {
				return false ;
			}
			if(this.author != obj1.author) {
				return false ;
			}
			return true ;
		}
		
	    
}

Driver Class

import java.util.*;
public class Driver {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		List<Book> library = new ArrayList<>() ;
		
		
		Book b1 = new Book(121, "Let us C", "Yashwant Kanetkar", "BPB", 8);
		Book b2 = new Book(233, "Operating System", "Galvin", "Wiley", 6);
		Book b3 = new Book(101, "Data Communications & Networking", "Forouzan", "Mc Graw Hill", 4);
		Book b4 = new Book(121, "Let us C", "Yashwant Kanetkar", "Mc Graw Hill", 11);
		
		library.add(b1);
		library.add(b2);
		library.add(b3);
		library.add(b4);
		List<Book> notDup = new ArrayList<>();
		boolean isSame = false ; 
		int duplicate = 0 ; 
		int notDuplicate = 0 ;
		int quantity = 0 ;
		for(int i = 0 ; i < library.size()-1 ; i++) {
			isSame = false ;
			for(int k = i+1 ; k < library.size() ; k++) {
				if(library.get(i).equals(library.get(k))) {
					duplicate++ ;
					System.out.println("No. of Duplicate Book :" + duplicate);
					isSame = true ;
					System.out.println(library.get(i));
				}
			}
			if(!isSame) {
				notDuplicate++ ;
				notDup.add(library.get(i));
				if(quantity < library.get(i).quantity) {
					quantity = library.get(i).quantity ;
				}
			}
		}
		
		
		for(Book k : notDup) {
			if(k.quantity == quantity) {
				System.out.println(k);
			}
		}
	}

}

OUTPUT

0 replies

Task - Collections - Finding Duplicates Using equals() #46

Uh oh!

Uh oh!

akash-coded Mar 4, 2022 Maintainer

Duplicate Books in a Library

Replies: 38 comments

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

akash-coded
Mar 4, 2022
Maintainer