POJ 2551

 1 #include<iostream>
 2 #include<stdio.h>
 3 #include<string>
 4 using namespace std;
 5
 6 //int my_pow(int ,int );
 7 int main()
 8 {
 9     //freopen("acm.acm","r",stdin);
10     int s;
11     int i;
12     int num;
13     while(cin>>s)
14     {
15         num = 0;
16         for(i = 0; ; ++ i)
17         {
18             num =  num*10 + 1;
19             if(num % s == 0)
20             {
21                 cout<<i+1<<endl;
22                 break;
23             }
24             else
25             {
26                 num %= s;
27             }
28         }
29         //cout<<num<<endl;
30
31
32     }
33 }
34 /*int my_pow(int a,int b)
35 {
36     if(b == 0)
37         return 1;
38     else
39     {
40         return a*my_pow(a,b - 1);
41     }
42 }*/