hdu 1061 Rightmost Digit（快速幂取模）

Problem Description

Given a positive integer N, you should output the most right digit of N^N.

Input

The input contains several test cases. The first line of the input is a single integer T which is the number of test cases. T test cases follow.
Each test case contains a single positive integer N(1<=N<=1,000,000,000).

Output

For each test case, you should output the rightmost digit of N^N.

Sample Input

2 3 4

Sample Output

7 6

Hint

In the first case, 3 * 3 * 3 = 27, so the rightmost digit is 7. In the second case, 4 * 4 * 4 * 4 = 256, so the rightmost digit is 6.

解题思路：简单的快速幂取模运算，水过！

AC代码：

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
LL mod_power(LL a,LL b,int mod){
    LL ans=1;
    while(b){
        if(b&1)ans=ans*a%mod;
        a=a*a%10;
        b>>=1;
    }
    return ans;
}
int main(){
    int t;LL n;
    while(cin>>t){
        while(t--){
            cin>>n;
            cout<<mod_power(n,n,10)<<endl;
        }
    }
    return 0;
}