题解 | #【模板】前缀和#

#include <iostream>
#include <vector>
using namespace std;

int main() 
{
    int n, q;
    cin >> n >> q;
    vector<long long> nums(n+1);
    for(int i = 1; i <= n;i++)
        cin >> nums[i];
    vector<long long> dp(n + 1);
    for(int i = 1; i <= n;i++)
        dp[i] = dp[i-1] + nums[i];
    while (q--)
    {
        int l, r;
        cin >> l >> r;
        cout << dp[r] - dp[l-1] << endl;
    }


}