51Nod-1004n^n的末位数字

#include  
#include  
#include  
#include  
using namespace std;  

int main(){
	int n, cnt, ans; 
	while(scanf("%d", &n) != EOF){
		cnt = n; 
		ans = 1; 
		n = n % 10; 
		while(cnt){
			if(cnt%2 == 1){
				ans = (ans * n) % 10; 
			}
			n = n * n % 10; 
			cnt = cnt / 2; 
		}
		printf("%d\n", ans%10 );
	}
	return 0; 
}