AcWing_795 前缀和(模板)

#include <bits/stdc++.h>
using namespace std;
int n, m;
const int N = 100010;
int s[N];
int main(){
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        cin >> s[i];
        s[i] += s[i - 1];
    }
    while(m --){
        int l, r;
        cin >> l >> r;
        cout << s[r] - s[l - 1] << endl;
    }
}