【数论，水题】UVa 10127 - Ones

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstdlib>
 4 #include<cmath>
 5 using namespace std;
 6 const int maxn = 10010;
 7 int main()
 8 {
 9     int n, p[maxn];
10     while(~scanf("%d", &n))
11     {
12         if(!n) {printf("0\n"); continue;}
13         int len = log10(n)+1;
14         int val = 0, x;
15         for(x = 0; x < len; x++)
16         {
17             val = val*10 + 1;
18         }
19         int res = 0;
20         if(val/n == 0)
21         {
22             val = val*10+1;
23             x++;
24         }
25         res = val%n;
26         while(res)
27         {
28             res = res*10+1;
29             res = res%n;
30             x++;
31         }
32         printf("%d\n", x);
33     }
34     return 0;
35 }