Two string - C++ vector class template

Twostring13.cpp

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

vector<int> compute_histogram(const string &s){
	const int n = s.size();
	vector<int> hist(128);
	for(int i = 0; i < n; ++i){ ++hist[s[i]]; }
	return hist;
}

int main(){
	ios_base::sync_with_stdio(false);
	int T;
	cin >> T;
	while(T--){
		string a, b;
		cin >> a >> b;
		const vector<int> ha = compute_histogram(a);
		const vector<int> hb = compute_histogram(b);
		bool answer = false;
		for(int i = 0; i < 128; ++i){
			if(ha[i] && hb[i]){ answer = true; }
		}
		cout << (answer ? "YES" : "NO") << endl;
	}
	return 0;
}