Submission #8

#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    int a[n];
    for(int i = 0; i < n; ++i) cin >> a[i];
    int q, p, l, r;
    cin >> q;
    long long sum = 0;
    while(q--) {
        cin >> p >> l >> r;
        if(p == 1) a[l - 1] = r;
        else {
            sum = 0;
            for(int j = l - 1; j < r; ++j) sum += a[j];
            cout << sum << '\n';
        }
    }
    return 0;
}