HDOJ1097 幂取模

#include"iostream"
#include"algorithm"
#include"sstream"
#include"cstdio"
#include"cstring"
#include"cctype"
#include"functional"
using namespace std;
int pow_mod(int a,int n,int m)
{
if(n==0) return 1;
int x=pow_mod(a,n/2,m);
long long ans=(long long)x*x%m;
if(n%2==1) ans=ans*a%m;
return int(ans);
}
int main()
{
int a,n;
while(cin>>a>>n)
cout<<pow_mod(a,n,10)<<endl;
return 0;
}