mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-25 06:51:58 +00:00
54 lines
828 B
C++
54 lines
828 B
C++
#pragma GCC optimize("Ofast")
|
|
|
|
#include <iostream>
|
|
#include <cmath>
|
|
#include <map>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
using std::cin;
|
|
using std::cout;
|
|
const char endl = '\n';
|
|
|
|
long long n, x;
|
|
std::map<long long, int> map;
|
|
|
|
inline int len(long long x) {
|
|
if (x == 0) return 0;
|
|
|
|
return (int)log10(x) + 1;
|
|
}
|
|
|
|
int dfs(long long x) {
|
|
if (map.count(x)) return map[x];
|
|
|
|
map[x] = 0x3f3f3f3f;
|
|
|
|
std::vector<int> a;
|
|
long long t = x;
|
|
while (t) {
|
|
a.push_back(t % 10);
|
|
t /= 10;
|
|
}
|
|
|
|
if (a.size() == n) return map[x] = 0;
|
|
|
|
for (int i : a) {
|
|
map[x] = std::min(map[x], dfs(x * i) + 1);
|
|
}
|
|
|
|
return map[x];
|
|
}
|
|
|
|
signed main() {
|
|
std::ios::sync_with_stdio(false);
|
|
|
|
cin >> n >> x;
|
|
|
|
int ans = dfs(x);
|
|
|
|
cout << (ans == 0x3f3f3f3f ? -1 : ans) << endl;
|
|
|
|
return 0;
|
|
}
|