ArraysLists.java

/*-- Comparing two lists' objects --*/

import java.util.*;

public class ArraysLists {

    static List<Integer> compareLists(List<Integer> a, List<Integer> b) {

        List<Integer> list1 = new ArrayList<Integer>();
        list1 = a;

        List<Integer> list2 = new ArrayList<Integer>();
        list2 = b;

        /* This line is tricky */

        /*
        
        Integer[] arr1 = new Integer[list1.size];
        arr1 = list1.toArray();
        The above two lines can be merged and can be written as:
        Integer[] arr1 = list1.toArray(new Integer[list1.size()]);

        */

        Integer[] arr1 = list1.toArray(new Integer[list1.size()]);

        Integer[] arr2 = list2.toArray(new Integer[list2.size()]);

        int aaa=0;
        int bbb=0;
        
        for(int i=0; i<list1.size(); i++){

            if(arr1[i]==arr2[i])
            {}

            else if(arr1[i]>arr2[i])
            aaa++;

            else if(arr1[i]<arr2[i])
            bbb++;
        }

        List<Integer> arrFinal = new ArrayList<Integer>();
        arrFinal.add(aaa);
        arrFinal.add(bbb);


        return arrFinal;

}
    
    /*-- Inputs from the main method --*/
    
    public static void main(String[] args){
    
        List<Integer> A = new ArrayList<>(new Integer(10));
        A.add(20);
        A.add(30);
        A.add(40);
        A.add(50);
        
        List<Integer> B = new ArrayList<>(new Integer(30));
        B.add(40);
        B.add(40);
        B.add(40);
        B.add(40);
        
        List<Integer> list = compareLists(A,B);
        
        for(int i=0; i<list.size(); i++){
            System.out.println(list.get(i));
        }
        
    }
    
}