How can I find two elements in an array that sum to k

Question

Suppose you are given an array of unsorted integers as

A = {3,4,5,1,4,2}

Input : 6 Output : {5,1}, {4,2}

Answer 1

public static void main(String[] args) {
    // TODO Auto-generated method stub

    int arr[]={4,2,6,8,9,3,1};
    int sum=10;
    int arr1[]=new int[sum];


    for(int x=0;x