nyoj473 A^B Problem (高速幂)

A^B Problem

时间限制:1000 ms  |  内存限制:65535 KB
难度:2
描写叙述
Give you two numbers a and b,how to know the a^b's the last digit number.It looks so easy,but everybody is too lazy to slove this problem,so they remit to you who is wise.
输入
There are mutiple test cases. Each test cases consists of two numbers a and b(0<=a,b<2^30)
输出
For each test case, you should output the a^b's last digit number.
例子输入
7 66
8 800
例子输出
9
6
提示
There is no such case in which a = 0 && b = 0。
来源
hdu
上传者
ACM_丁国强

 
#include <stdio.h>
int main()
{
	int a,b,_a,s;
	while(scanf("%d %d",&a,&b)!=EOF)
	{
		if(a==0&&b==0)
		break;
		s=1;
		while(b)
		{
			if(s>=10)
			s=s%10;
			if(a>=10)
			a=a%10;
			if(b%2==1)
			s=s*a;
			a=a*a;
			b=b/2;	
		}
		if(s>=10)
		s=s%10;
		printf("%d\n",s);
	}
	return 0;
}                

posted @ 2017-05-21 10:48  yxysuanfa  阅读(144)  评论(0编辑  收藏  举报