HDU 1097 A hard puzzle【快速幂取模】

A hard puzzle

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 37008 Accepted Submission(s): 13208

Problem Description

lcy gives a hard puzzle to feng5166,lwg,JGShining and Ignatius: gave a and b,how to know the a^b.everybody objects to this BT problem,so lcy makes the problem easier than begin.
this puzzle describes that: gave a and b,how to know the a^b's the last digit number.But everybody is too lazy to slove this problem,so they remit to you who is wise.

Input

There are mutiple test cases. Each test cases consists of two numbers a and b(0<a,b<=2^30)

Output

For each test case, you should output the a^b's last digit number.

Sample Input

7 668 800

Sample Output

96

快速幂对10 取模

唯一的发现是，进行参数传递的时候，先进行取模，否则会直接溢出，没注意到，错了一次！

#include<stdio.h>int qm(int n,int m){int s=1;while(m){if(m&1){s=(s*n)%10;}n=(n*n)%10;m>>=1;}return s;}int main(){//freopen("shuju.txt","r",stdin);int a,b;while(~scanf("%d%d",&a,&b)){int ans=qm(a%10,b);printf("%d\n",ans);}return 0;}