hdu2035【二分快速幂】

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 using namespace std;
 5 
 6 int quickpow(int a, int b, int mod) {
 7     int ans = 1;
 8     while(b) {
 9         if(b & 1) {
10             ans = ans * a % mod;
11         }
12         a  = a * a % mod;
13         b >>= 1;
14     }    
15     return ans;
16 }
17 
18 int main() {
19     int a, b;
20     while(scanf("%d%d", &a, &b), a + b) {
21         printf("%d\n", quickpow(a, b, 1000));
22     }
23     return 0;
24 }
25