Envío 519

Código

#include <iostream>
#include <vector>

using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<int> arr = vector<int>(n);
    vector<int> cache = vector<int>(n);

    int sum = 0;
    for (int i = 0; i < n; i++)
    {
        cin >> arr[i];

        // update cache
        sum += arr[i];
        cache[i] = sum;
    }

    int m, p, q;
    cin >> m;
    for (int i = 0; i < m; i++)
    {
        cin >> p >> q;
        if (p == 0)
            sum = cache[q];
        else
            sum = cache[q] - cache[p - 1];

        cout << sum << endl;
    }

    return 0;
}