Submission

Status:

[P-SSSSSSSS][-SSSS]

Score: 0

User: njoop

Problemset: ขนมของเซ้น143 (v.ยาก)

Language: cpp

Time: 0.002 second

Submitted On: 2024-11-30 22:50:10

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

int n, l=1, r, mid, val;

int findAns(int num) {
    return abs(mid*(mid+1)-n*(n+1)/2);
}

signed main() {
    cin >> n;
    r=n;
    while(l < r) {
        mid = l+(r-l)/2;
        if(mid*(mid+1)/2 < n*(n+1)/2-mid*(mid+1)/2) {
            l = mid+1;
        } else {
            r = mid;
        }
    }
    if(findAns(l) > findAns(l+1)) cout << l-1;
    else cout << l;
    return 0;
}