Task - String Programs - Reverse a String

[akash-coded]

Write a Java program to reverse a given string preserving the position of spaces.

Example:

India Is my country --> yrtnu oc ym sIaidnI

[abhiraj2k]

package strings;

public class ReverseWords {
    static String reverse(String str) {
        String[] strAr = str.split(" ");
        int i = 0;
        int j = strAr.length - 1;
        while (i < j) {
            strAr[i] = reverseWord(strAr[i]);
            strAr[j] = reverseWord(strAr[j]);
            String temp = strAr[i];
            strAr[i] = strAr[j];
            strAr[j] = temp;
            i++;
            j--;
        }
        return String.join(" ", strAr);
    }

    static String reverseWord(String str) {
        char[] strAr = str.toCharArray();
        int i = 0;
        int j = str.length() - 1;
        while (i < j) {
            char temp = strAr[i];
            strAr[i] = strAr[j];
            strAr[j] = temp;
            i++;
            j--;
        }
        return String.valueOf(strAr);
    }

    public static void main(String[] args) {
        String str = "India Is my country";
        System.out.println(reverse(str));
    }
}

[Sarfinaa]

public class ReverseString {
    public static String reverse(String s) {
        StringBuilder sb = new StringBuilder(s);
        return sb.reverse().toString();
    }

    public static void main(String[] args) {
        String s = "India Is my country";
        String[] sarr = s.split(" ");
        String ans = "";
        for (String str : sarr) {
            ans = reverse(str) + " " + ans;
        }
        System.out.println("Originial:" + s);
        System.out.println("After Reversing:" + ans);
    }
}

[rakeshGit419]

public class ReverseString {
    public static void main(String[] args) {
        String str = "India Is My Country";
        String[] strArr = str.split(" ");
        for(int i=strArr.length-1;i>=0;i--){
            System.out.print(reverse(strArr[i])+" ");
        }
    }

    private static String reverse(String string) {
        String res = "";
        for(int i=string.length()-1;i>=0;i--){
            res+=string.charAt(i);
        }
        return res;
    }
}

[Gaurav-Joshi-31]

public class Reverse {
    static String reverse(String s) {
        char[] arr = s.toCharArray();
        int i = 0, j = arr.length - 1;
        while (i < j) {
            if (arr[i] == ' ')
                i++;
            if (arr[j] == ' ')
                j--;
            char temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
            i++;
            j--;
        }

        return new String(arr);
    }

    public static void main(String[] args) {
        String s = "India is my country";
        System.out.println(s + "-->" + reverse(s));

    }
}

[amruth2211]

`package Week4;

import java.util.Scanner;

public class ReverseString {

public static void reverse(String s) {
        String p = "";
    int n = s.length() - 1;
    for (int i = n; i >= 0; i--) {
        p += s.charAt(i);
    }
    String res = p.replace(" ", "");

    char[] resArr = res.toCharArray();
    String output = "";

    int len = s.length();
    int i = 0, j = 0;
    while (i < len) {
        if (s.charAt(i) == ' ') {
            output += " ";
        } else {
            output += resArr[j++];
        }
        i++;
    }
    System.out.println(output);
}

public static void main(String[] args) {
    Scanner scr = new Scanner(System.in);
    System.out.println("Enter the string ");
    String s = scr.nextLine();
    reverse(s);
    scr.close();
}

}
`

[Khyati-tripathi]

package StringModule;

import java.util.*;

public class PreserveWhitespaces {
    static void reverseString(String str) {
        char[] ch = str.toCharArray();
        int n = str.length();
        char[] res = new char[n];

        for (int i = 0; i < ch.length; i++) {
            if (ch[i] == ' ') {
                res[i] = ' ';
            }
        }
        int j = n - 1;
        for (int i = 0; i < n; i++) {
            if (ch[i] != ' ') {
                if (res[j] == ' ') {
                    j--;

                }

                res[j--] = ch[i];
            }
        }
        System.out.println(String.valueOf(res));

    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        reverseString(s);

    }

}

[sruthi-15-sketch]

import java.util.Scanner;
public class Main {
static String reverse(String s){
int l=s.length();
String res="";
for(int i=l-1;i>=0;i--){
res+=s.charAt(i);
}
return res;
}
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
String s=sc.nextLine();
String s1=s.replace(" ","");
String rev=reverse(s1);
String result="";
int j=0;
for(int i=0;i<s.length();i++){
if (s.charAt(i)==' '){
result+=" ";
}
else{
result+=rev.charAt(j++);
}
}
System.out.println(result);

}

}

[RohitNaikade1]

package Strings;

public class ReverseWithSpaces {
    public static void main(String[] args) {
        String str="India is my country";
        String answer="";
        int j=str.length()-1;
        int i=0;
        for(;i<str.length();i++){
            if(str.charAt(i)==' '){
                answer+=" ";
                continue;
            }
            if(str.charAt(j)==' '){
                j--;
                i--;
                continue;
            }
            answer+=str.charAt(j);
            j--;
        }

        while(i>str.length()){
            answer+=str.charAt(i);
        }

        System.out.println("Reversed String: "+answer);
    }
}

[KaminiJha]

public class ReverseString {
    public static void main(String[] args) {
        //create string array ->split by space
        String str="India Is my country";
        String[] strArr=str.split(" ");
        //reverse each string in array
        int l=strArr.length;
        String ans="";
        for(int i=l-1;i>=0;i--)
        {
            strArr[i]=reverse(strArr[i]);
            ans+=strArr[i];
        }
        // System.out.println(ans);
        int len=str.length();
        int k=0;
        String res="";
        for(int i=0;i<len;i++)
        {
            // System.out.println(res);
            if(str.charAt(i)==' ')
            {
                res+=" ";
            }
            else{
                res+=ans.charAt(k);
                k++;
            }
            
        }
        System.out.println(res);
    }
    public static String reverse(String s)
    {
        String ans="";
        int i=s.length()-1;
        while(i>=0)
        {
            ans+=s.charAt(i);
            i--;
        }
        return ans;
    }
}

[Ashwesh09]

import java.util.ArrayList;

public class StringReverse {
    public static void main(String[] args) {
        String in = "India Is my country";
        ArrayList<Integer> space = new ArrayList<>();
        for (int i = 0; i < in.length(); i++) {
            if (in.charAt(i) == ' ')
                space.add(i);
        }
        String temp = in.replaceAll("\\s", "");
        StringBuilder res = new StringBuilder("");
        for (int i = 0; i < temp.length(); i++) {
            res.append(temp.charAt(temp.length() - i - 1));
        }
        for (int i = 0; i < space.size(); i++) {
            res.insert(space.get(i), " ");
        }
        System.out.println(res);
    }
}

[Kavitha-Golamari]

import java.util.Scanner;
public class Reversestr{
static void reverseString(String str){
char[] str1 = str.toCharArray();
char[] str2 = new char[str1.length];
for (int i = 0; i < str1.length; i++) {
if (str1[i] == ' ') {
str2[i] = ' ';
}
}
int j = str2.length-1;
for (int i = 0; i < str1.length; i++){
if (str1[i] != ' ')
{
if(str2[j] == ' '){
j--;
}
str2[j] = str1[i];
j--;
}
}
System.out.println(str+" --> "+String.valueOf(str2));
}
public static void main(String[] args)
{
Scanner sc=new Scanner(System.in);
String str=sc.nextLine();
reverseString(str);

    }
}

[vysh675]

public class reversestr {

public static void main(String[] args) {
    String str = "welcome to my place";
    String res = "";
    System.out.println("string before reverseal"+str);
    for (int i = str.length() - 1; i >= 0; i--) {
        res += str.charAt(i);
    }
    str = res;
    System.out.println("string after reverseal"+str);
    
}

}

[Shubhi27]

package session14;

public class ReverseStringSpaces {
    static void reverseString(String str) {
        char[] arr = str.toCharArray();
        int i = 0;
        int j = arr.length - 1;
        while (i < j) {
            if (arr[i] == ' ') {
                i++;
            } else if (arr[j] == ' ') {
                j--;
            } else {
                char k = arr[i];
                arr[i] = arr[j];
                arr[j] = k;
                i++;
                j--;
            }

        }

        System.out.println("Reversed String will be: " + String.valueOf(arr));
    }

    public static void main(String[] args) {
        String str = "India is my country";
        reverseString(str);

    }
}

[Amrit-Raj22]

package week3d4;

public class RevString {

    static void reverse(String s) {
        // String str = s.replaceAll(" ", "");
        String ans = "";
        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == ' ') {
                ans += " ";

            } else if (s.charAt(s.length() - i - 1) == ' ') {
                continue;
            }
            ans += s.charAt(s.length() - i - 1);

        }
        System.out.println(ans);

    }

    public static void main(String[] args) {
        String s = "India Is my country";
        reverse(s);
    }

}

[Ashritha-sd]

class Rev
{
public static void main(String[] args)
{
String s[]= "India Is my country".split(" ");
String ans = "";
for(int i=s.length-1;i>=0;i--)
{
ans+=s[i]+" ";
}
//System.out.println(StringFormatter.reverseWord(ans));
String word[]=ans.split(" ");
String f="";
for(String w:word)
{
StringBuilder sb=new StringBuilder(w);
sb.reverse().toString();
f+=sb+" ";
}
System.out.println(f);
}
}

[ratnadeepikavuddagiri]

`import java.util.Scanner;
public class StringReverse {

public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    String str=scanner.nextLine();
    System.out.println(reverseString(str));
}
static String reverseString(String s) {
    char[] ch = s.toCharArray();
    int i = 0, j = ch.length - 1;
    while (i < j) {
        if (ch[i] == ' ')
            i++;
        if (ch[j] == ' ')
            j--;
        char temp = ch[i];
        ch[i] = ch[j];
        ch[j] = temp;
        i++;
        j--;
    }
    return new String(ch);
}

}
`

[ShraddhaPenshanwar]

`package all_strings;

import java.util.*;

public class ReverseStringWithSpaces {

public static String reverse(String s) {
    StringBuilder sb = new StringBuilder(s);
    return sb.reverse().toString();
}

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String input = sc.nextLine();
    String str[] = input.split("\\s+");

    String ans = "";
    for (String strele : str) {
        ans = reverse(strele) + ans;
    }

    System.out.println(ans);
    int p = 0;
    String rev = "";
    int k = 0;
    while (k < input.length()) {

        if (input.charAt(k) == ' ') {
            rev += " ";

        } else {

            rev += ans.charAt(p);

            p++;
        }
        k++;

    }

    System.out.println(rev);
}

}
`

[lalit-ky]

public class ReverseWithoutSpaces {
    static String reverse(String str) {
        int end = str.length() - 1;
        String ans = "";
        for (int i = 0; i <= end; i++) {
            if (str.charAt(i) == ' ') {
                ans += " ";
            }
            if (str.charAt(end - i) == ' ') {
                continue;
            }
            ans += str.charAt(end - i);
        }
        return ans;
    }

    public static void main(String[] args) {
        String str = "India is my country";
        System.out.println(reverse(str));
    }
}

[deepak775035]

package session14;

public class WordReversal {
    
    public static void printReveredWord(String str) {
        String[] strArr = str.split(" ");
        
        for (int i = strArr.length-1; i > -1 ; i--) {
            System.out.print(new StringBuilder(strArr[i]).reverse()+" ");
        }

        // for (String string : strArr) {
        //     System.out.print(new StringBuilder(string).reverse()+" ");
        // }
        
    }
    
    public static void main(String[] args) {
        String str = "India Is my country";
        System.out.println(str);
        printReveredWord(str);
    }
}

[SrideviYamala]

public class ReverseString {
    public static void main(String[] args) {
        String s="India Is my country";
        char[] ch = s.toCharArray();
        for (int i = 0, j = ch.length - 1; i < j; i++, j--) {
            if (ch[j] == ' ') {
                i--;
            } else if (ch[i] == ' ') {
                j++;
            } else {
                char temp;
                temp = ch[i];
                ch[i] = ch[j];
                ch[j] = temp;
            }
        }
        System.out.println(ch);
    }
}

[Harshita-Joshi]

package Strings;
import java.util.*;

public class SentenceWordReverse {

    static String reverseString(String str){

        String res = "";
        for(int i=str.length()-1; i>=0; i--){
            res += str.charAt(i);
        }
        
        res = res.replace(" ","");
        
        char[] resArr = res.toCharArray();
        res = "";

        int len = str.length();
        int i=0, j=0;
        while(i<len){
            if(str.charAt(i)==' '){
                res += " ";
            }else{
                res += resArr[j++];
            }
            i++;
        }
       
        return res;
    }

    public static void main(String[] args) {
        
        Scanner scn = new Scanner(System.in);
        String str = scn.nextLine();

        String res = reverseString(str);
        System.out.println(res);
    }
}

[PavanArvapally]

`public class ReverseString {
public static void main(String[] args) {
String string = "India is my country";
reverseString(string);
}

private static void reverseString(String string) {
    System.out.println("Original String : \n" + string);
    System.out.println("After reversing : ");

    int length = string.length();

    for(int i = 0, j = length-1; i<length; i++,j--){
        if(string.charAt(j) == ' '){
            j--;
        }
        if(string.charAt(i) == ' '){
            System.out.print(" ");
            j++;
        }
        
        else{
            System.out.print(string.charAt(j));
        }
        
    }
} 

}`

[shreiyarandive]

public class StringReverse {

    public static String reverse(String s) {
        String revStr = "";
        char[] c = s.toCharArray();
        for (int i = c.length - 1; i >= 0; i--) {
            revStr += c[i];
        }
        return revStr;
    }

    public static void main(String[] args) {
        String inpStr = "India is my country";

        String[] str = inpStr.split(" ");

        String outStr = "";

        for (int i = str.length - 1; i >= 0; i--) {
            outStr += reverse(str[i]) + " ";
        }

        System.out.println("Reversed String is: " + outStr);
    }
}

[ujjwal18bit1167]

public class ReversedStr {
    public static void main(String[] args) {
        String str = "India Is My Country";
        String[] strArr = str.split(" ");
        for(int i=strArr.length-1;i>=0;i--){
            System.out.print(rev(strArr[i])+" ");
        }
    }

    private static String rev(String string) {
        String res = "";
        for(int i=string.length()-1;i>=0;i--){
            res+=string.charAt(i);
        }
        return res;
    }
}

[GantaGreeshma]

`public class StringreverseWord {
public static String reverseWord(String str) {
int n = str.length();
String rev = "";
for (int i = n - 1; i >= 0; i--) {
rev += str.charAt(i);
}
return rev;
}

public static void main(String[] args) {
    String str = "India Is My Country";
    String[] arr = str.split(" ");
    for (int i = arr.length - 1; i >= 0; i--) {
        System.out.print(reverseWord(arr[i]) + " ");
    }
}

}
`

[Prem-3]

`
public class StringRev {
public static void main(String[] args) {
String str = "India Is my country";
String reverseStr = "";

    for (int i = str.length() - 1; i >= 0; i--) {
        reverseStr = reverseStr + str.charAt(i);
    }
    System.out.println(reverseStr);
}

}`

[Batchusatyasri]

public class Stringreverse {
public static String reverse(String s) {
StringBuilder sb = new StringBuilder(s);
return sb.reverse().toString();
}

public static void main(String[] args) {
    String s = "India Is my country";
    String[] arr = s.split(" ");
    String result = "";
    for (String str : arr) {
        result = reverse(str) + " " + result;
    }
    System.out.println("Befor reversing:" + s);
    System.out.println("After reversing:" + result);
}

}

[charani712]

public class ReverseString {
public static void main(String[] args) {
String str = "India Is My Country";
String[] strArr = str.split(" ");
for(int i=strArr.length-1;i>=0;i--){
System.out.print(reverse(strArr[i])+" ");
}
}

private static String reverse(String string) {
    String res = "";
    for(int i=string.length()-1;i>=0;i--){
        res+=string.charAt(i);
    }
    return res;
}

}

[mkaifahmed]

public class Reverse {
    static String reverse(String s) {
        char[] arr = s.toCharArray();
        int i = 0, j = arr.length - 1;
        while (i < j) {
            if (arr[i] == ' ')
                i++;
            if (arr[j] == ' ')
                j--;
            char temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
            i++;
            j--;
        }

        return new String(arr);
    }

    public static void main(String[] args) {
        String s = "India is my country";
        System.out.println(s + "-->" + reverse(s));

    }
}

[VigneshVishwa]

import java.util.*;

public class ReverseString {
    public static String reverse(String s) {
        StringBuilder sb = new StringBuilder(s);
        return sb.reverse().toString() + " ";
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        StringBuilder sb1 = new StringBuilder();
        System.out.println("Enter the string:");
        String str = sc.nextLine();
        int n = str.length() - 1;
        String[] parts = str.split(" ");
        System.out.println("rversed string:");
        for (int i = parts.length - 1; i > -1; --i) {
            sb1.append(reverse(parts[i]));
        }
        String newstr = sb1.toString();
        for (int i = 0; i < str.length(); i++) {
            if (str.charAt(i) == ' ') {
                System.out.print(" " + newstr.charAt(i));
            } else
                System.out.print(newstr.charAt(i));
        }
    }
}