백준 5940 Math Practice (USACO November 2010 Bronze 3번)

문제 링크: https://www.acmicpc.net/problem/5940

5940번: Math Practice

#include <bits/stdc++.h>
using namespace std;
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
 
    int A, B;
    cin >> A >> B;
    for(int i = A + 1; i <= 62; i++) {
        long long n = 1;
        int power = i;
        while(power--) n *= 2;
        while(n > 9) n /= 10;
        if(n == B) {
            cout << i << '\n';
            return 0;
        }
    }
    cout << 0 << '\n';
    return 0;
}