#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <string>
#include <math.h>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <stdio.h>
#include <numeric>
#include <iomanip>
#include <random>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
long long n;
cin >> n;
long long l = 0, r = 1e18;
while (l + 1 < r) {
long long m = (l + r) / 2;
if (m > (2e18 + m - 1) / (m + 1) && m * (m + 1) / 2 > n) {
r = m;
} else {
l = m;
}
}
if (l * (l + 1) / 2 == n) cout << l * l;
else {
cout << l * l + (n - l * (l + 1) / 2) * 2 - 1;
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |