题解 | #【模板】静态区间和（前缀和）#（cpp）

#include "bits/stdc++.h"

using namespace std;
#define int long long
#define endl "\n"
#define PII pair<int,int>
#define PIII pair<int,PII>
const int MOD = 1e9 + 7;
const int N = 3e5;

void slu() {
    int n, m;
    cin >> n >> m;
    vector<int> a(n + 1, 0);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        a[i] += a[i - 1];
    }
    for (int i = 0; i < m; i++) {
        int l, r;
        cin >> l >> r;
        cout << a[r] - a[--l] << endl;
    }
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T;
//    cin >> T;
    T = 1;
    while (T--)slu();

}