本题题解（法神姐有更短的吗，请指教）

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll a,b,s = 1;
int main()
{
    freopen("pow.in","r",stdin);
    freopen("pow.out","w",stdout);
    cin >> a >> b;
    for (int i = 0; i < b; ++i)
        s *= a,s %= 1000;
    printf("%03lld",s);
    fclose(stdin);
    fclose(stdout);
    return 0;
}