题解

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

int main() {
    int n;
    cin >> n;

    string s;
    while (n > 0) {
        s += to_string(n % 2);
        n /= 2;
    }
    reverse(s.begin(), s.end());
    cout << s << endl;
    return 0;
}