1104. Don’t Ask Woman about Her Age（数论）

a*b^n(mod(b-1) =a(mod(b-1)

http://acm.timus.ru/problem.aspx?space=1&num=1104

 1 #include <stdio.h>
 2 #include <string.h>
 3
 4 char str[1000000 + 10];
 5
 6 int CharToInt(char c)
 7 {
 8     if(c>=‘0‘ && c<=‘9‘)
 9         return c - ‘0‘;
10     return c - ‘A‘ + 10;
11 }
12 int main()
13 {
14     scanf("%s",str);
15     int i,n = strlen(str);
16     int sum = 0;
17     char ch = ‘ ‘;
18     for(i=0; i<n; ++i)
19     {
20         if(str[i] > ch) ch = str[i];
21         sum += CharToInt(str[i]);
22     }
23     if(ch <=‘9‘) i = ch - ‘0‘;
24     else i = ch -‘A‘ + 10;
25     if(i+1<2) i = 2;
26     else i++;
27     for(;i<=36; ++i)
28         if(sum % (i-1) == 0)
29         {
30
31             break;
32         }
33     if(i<=36)
34         printf("%d\n",i);
35     else
36         puts("No solution.");
37 }