A3oTOW - Online C++0x Compiler & Debugging Tool

#include <bits/stdc++.h>
using namespace std;

int main() {
	int size,k;
    cin>>size>>k;
    int A[size];
    for(int i = 0 ; i<size ; i++){
    	cin>>A[i];
    }
    map<int,int>hashmap;
    int totalCount = 0;
    for(int i = size-1 ; i>=0 ; i--){
        if(hashmap.find(A[i]-k)!=hashmap.end()){
            totalCount += hashmap[(A[i]-k)];
        }
        hashmap[A[i]]++;
    }
    cout<<totalCount<<endl;
	return 0;
}