EOJ3134. 短信激活码（大数幂取模）

题面

输入只有5位，所以转化为long long类型用快速幂取模

前面补0的写法printf("%05lld\n",ans);如果ans不足5位会在前面补0

 #include<bits/stdc++.h>
 using namespace std;
 long long mod_exp(long long a, long long b, long long c)        //快速幂取余a^b%c
 {
     long long res, t;
     res =  % c;
     t = a % c;
     while (b)
     {
         if (b & )
         {
             res = res * t % c;
         }
         t = t * t % c;
         b >>= ;
     }
     return res;
 }
 int main()
 {
     int t;
     while(~scanf("%d",&t))
     {
         int cases=-;
         while(t--)
         {
             cases++;
             char s[],s2[];
             scanf("%s",s);
             s2[]=s[];
             s2[]=s[];
             s2[]=s[];
             s2[]=s[];
             s2[]=s[];
             long long temp=(s2[]-''+)*+(s2[]-''+)*+(s2[]-''+)*+(s2[]-''+)*+(s2[]-''+)*;
             printf("case #%d:\n%05lld\n",cases,mod_exp(temp,,));
         }
     }
     return ;
 }