PairWithGivenDifference.java

/**
Given an one-dimensional unsorted array A containing N integers.

You are also given an integer B, find if there exists a pair of elements in the array whose difference is B.

Return 1 if any such pair exists else return 0.



Problem Constraints

    1 <= N <= 105
    -103 <= A[i] <= 103
    -105 <= B <= 105



Input Format

First argument is an integer array A of size N.

Second argument is an integer B.



Output Format

Return 1 if any such pair exists else return 0.


Example Input

Input 1:

 A = [5, 10, 3, 2, 50, 80]
 B = 78

Input 2:

 A = [-10, 20]
 B = 30



Example Output

Output 1:

 1

Output 2:

 1



Example Explanation

Explanation 1:

 Pair (80, 2) gives a difference of 78.

Explanation 2:

 Pair (20, -10) gives a difference of 30 i.e 20 - (-10) => 20 + 10 => 30

**/




    public class Solution {
        public int solve(int[] A, int B) {
            if(B == 0)
            {
                Set<Integer> set = new HashSet<Integer>();
                for(int i=0; i<A.length; i++)
                {
                    if(set.contains(A[i]))
                    {
                        return 1;
                    }
                    set.add(A[i]);
                }
                    return 0;
            }
            Map<Integer, Integer> map = new HashMap<Integer, Integer>();
            for(int i=0; i<A.length; i++)
            {
                map.put(A[i], i);
            }
            for(int i=0; i<A.length; i++)
            {
                if(map.containsKey(A[i] + B))
                {
                    return 1;
                }
            }
            return 0;
            
        }
    }