Submission #551386

#	Time	Username	Problem	Language	Result	Execution time	Memory
551386		Olympia	Odd-even (IZhO11_oddeven)	C++17	0 / 100	1 ms	468 KiB

oddeven

#include <iostream>
#include <vector>
#include <iomanip>
#include <algorithm>
#include <cassert>
#include <map>
#include <complex>
#include <cmath>
#include <set>
#include <queue>
using namespace std;

#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    //int t;
    //cin >> t;
    //while (t--) {
    int64_t n; cin >> n;
    int64_t sq = (1 + sqrt(1 + 8 * n))/2;
        if (n == 1) {
            cout << 1 << '\n';
        } else if (n == 4) {
            cout << "5\n";
        } else {
            assert(sq * (sq + 1)/2 >= n);
            assert((sq - 1) * sq/2 <= n);
            cout << sq * sq + 2 *(n - (sq + 1) * sq/2) << '\n';
        }
    //}
}

Compilation message (stderr)

oddeven.cpp:14: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   14 | #pragma GCC optimization ("O3")
      | 
oddeven.cpp:15: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   15 | #pragma GCC optimization ("unroll-loops")
      |

• Subtask 1: 0 / 100