杭电1097题目：下面是我的编程,求指教,为什么老师说time limited

//
#include
int main()
{
int i, n, a, b;
while(scanf("%d%d", &a, &b) != EOF)
{
n = a % 10;
switch(n)
{
case 0:
case 1:
case 5:
case 6:
printf("%d", n); //尾数为0,1,5,6 时, a^b以后还是一样的
break;
case 2: //尾数为2
if(b % 4 == 0)printf("6");
else if(b % 4 == 1)printf("2");
else if(b % 4 == 2)printf("4");
else printf("8");
break;
case 3: //尾数为3
if(b % 4 == 0)printf("1");
else if(b % 4 == 1)printf("3");
else if(b % 4 == 2)printf("9");
else printf("7");
break;
case 4:
if(b % 2)printf("4");
else printf("6");
break;
case 7:
if(b % 4 == 0)printf("1");
else if(b % 4 == 1)printf("7");
else if(b % 4 == 2)printf("9");
else printf("3");
break;
case 8:
if(b % 4 == 0)printf("6");
else if(b % 4 == 1)printf("8");
else if(b % 4 == 2)printf("4");
else printf("2");
break;
case 9:
if(b % 2)printf("9");
else printf("1");
break;
}
printf("n");
}
}
//祝学习进步,更上一层楼 *^_^* !