B3612 【深进1.例1】求区间和

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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    vector<long long> pre(n + 1, 0);
    for (int i = 1; i <= n; i++) {
        long long x;
        cin >> x;
        pre[i] = pre[i - 1] + x;
    }

    int m;
    cin >> m;
    while (m--) {
        int l, r;
        cin >> l >> r;
        cout << pre[r] - pre[l - 1] << "\n";
    }
    return 0;
}