Submission #29492199

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Source Code Expand

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

using ll = long long;

template <class F> ll optimize(int low, int high, const F& f) {
    while (high - low > 2) {
        const int m1 = (low + high) / 2;
        const int m2 = m1 + 1;
        if (f(m1) < f(m2)) {
            low = m1;
        } else {
            high = m2;
        }
    }
    return f(low + 1);
}

void solve() {
    int n, m;
    cin >> n >> m;
    ll a = 0, b = 0, ans = numeric_limits<ll>::min();
    for (int i = 0; i < n; ++i) {
        ll x, y;
        cin >> x >> y;
        const auto f = [&](const int k) {
            return a + b * k + x * k * (k + 1) / 2;
        };
        if (x > 0) {
            ans = max(ans, f(1));
            ans = max(ans, f(y));
        } else {
            ans = max(ans, optimize(0, y + 1, f));
        }
        a = f(y);
        b += x * y;
    }
    cout << ans << '\n';
}

int main() {
    int t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

Submission Info

Judge Result