javalab23.java

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

public class javalab23 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList <Integer> List1 = new ArrayList<>();
        System.out.print("Enter number of elements in the Int type List1: ");
        int n = sc.nextInt();
        int st;
        for(int i = 0;i < n; i++){
            System.out.println(" Enter element " + (i+1) + ":");
            st = sc.nextInt();
            List1.add(st);
        }
        ArrayList <Integer> List2 = new ArrayList<>();
        System.out.print("Enter number of elements in the Int type List2: ");
        int n1 = sc.nextInt();
        for(int i = 0;i < n1; i++){
            System.out.println(" Enter element " + (i+1) + ":");
            st = sc.nextInt();
            List2.add(st);
        }
        ArrayList <Integer> res = alternate(List1,List2);
        System.out.println("List 1: " + List1);
        System.out.println("List 2: " + List2);
        System.out.println("Resulted array: " + res);
    }

    static ArrayList<Integer> alternate(ArrayList<Integer> list1, ArrayList<Integer> list2){
        ArrayList<Integer> list3 = new ArrayList<>();
        int i = 0;
        int j = 0;
        while(i<list1.size() || j<list2.size()){
            if(i<list1.size())
            {
                list3.add(list1.get(i++));
            }
            if(j<list2.size())
            {
                list3.add(list2.get(j++));
            }
        }
        return list3;
    }
}