(c++) 백준 "2292) 벌집"

https://www.acmicpc.net/problem/2292

2292번: 벌집

---

#include <iostream>
#include <cmath>
using namespace std;

int main() {
    int N; cin >> N;
    int num = 0;
    if (N == 1) {
        cout << 1 << endl;
        return 0;
    }
    N = ceil((N - 1) / 6.0);
    for (int i = 0; num <= N; i++) {
        num += i+1;
        if (N <= num) {
            cout << i+2 << endl;
            return 0;
        }
    }
    return 0;
}