interview.java

import java.util.HashMap;

public class Interview {

	public static boolean sum(int[] A, int b){
		HashMap<Integer, Integer> hash = new HashMap<Integer, Integer>(); 
		
		for (int i = 0; i<A.length; i++){
			hash.put(A[i], i);
		}
		
		for (int i = 0; i<A.length; i++){
			if(hash.get(b-A[i])!= null && hash.get(b-A[i]) != i){
				return true;
			}
		}
		return false;
	}
	
	public static void main(String[] args) {
		int [] A = {2, 2, 2, 2, 1, 2, 1, 2, 1, 3};
		System.out.println(sum(A, 200));
		System.out.println(sum(A, 4));
		
	}

}