백준 1300번 C++ 풀이

#include <iostream>
#include <queue>
#define MAX 35002
using namespace std;
queue<int> q;
//queue<int> result;

long long n;
long long k;
long long answer;
void find(long long start, long long end) {
    if (start >= end) return;
    auto middle = (start + end) /2;
    auto cnt = 0;
    for (auto i=1; i<=n; i++){
        cnt += min( n,middle/i);
    }
    if (cnt >= k){
        answer = middle;
        find(start, middle);
    }else {
        find(middle+1, end);
    }
}
int main() {
    cin.tie(NULL);
    ios::sync_with_stdio(false);
    cin >> n >> k;
    find(0, min( n*n+1, 1000000000LL) +1);
    cout << answer;
    return 0;

}