Remove from ends (C++)

#include <bits/stdc++.h>

using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++)
        cin >> a[i];

    int64_t ans = INT_MIN, sum = 0;
    for (int x : a) {
        sum += x;
        ans = max(ans, sum);
        if (sum < 0)
            sum = 0;
    }

    cout << ans;
    return 0;
}