Submission

Status:

[PPPPPPPPPP][PPPPP]

Score: 100

User: Pera

Problemset: ขนมของเซ้น143 (v.ยาก)

Language: cpp

Time: 0.002 second

Submitted On: 2025-03-27 09:56:22

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

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    long long n; cin >> n;
    long long totalSum = (n * (n + 1)) / 2;
    long long minDiff = LLONG_MAX;
    long long low = 1;
    long long high = n - 1;

    while (low <= high) {
        long long mid = low + (high - low) / 2;
        long long sumA = (mid * (mid + 1)) / 2;
        long long sumB = totalSum - sumA;
        long long diff = abs(sumA - sumB);
        minDiff = min(minDiff, diff);

        if (sumA * 2 < totalSum) {
            low = mid + 1;
        } else {
            high = mid - 1;
        }
    }

    cout << minDiff << '\n';
}