CPP0209 - TÍNH TỔNG TRONG KHOẢNG

#include<iostream>
#include<vector>
using namespace std;
int sum(vector<int> m, int a, int b) {
	int x = 0;
		for (int i = a-1; i < b; i++)
			x += m[i];
	return x;
}
int main() {
	int t; cin >> t;
	while (t--) {
		int n, k; cin >> n >> k;
		vector<int> m(n);
		for (int i = 0; i < n; i++)cin >> m[i];
		
		while(k--){
			int a, b; cin >> a >> b;
		cout << sum(m, a, b) << endl;
		}
	}
}