hdu Rightmost Digit

Rightmost Digit

Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 65536/32768K (Java/Other)

Total Submission(s) : 24   Accepted Submission(s) : 11

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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.

Author

Ignatius.L

一开始忽略了数很大，上来就编了，给的数据一测试对了，超兴奋的交上去了，结果却是超时。

当时的代码是：

#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
    long long int i,j,m,n,s;

    cin>>n;
    for(j=0;j<n;j++)
    {
        cin>>s;
        m=1;
        for(i=0;i<s;i++)
        {

            m=(m*(s%10))%10;
        }

        cout<<m<<endl;
    }
    return 0;
}

一定要想方法解决超时问题，最终自己还是没解决，求助大神后才顿悟。

正确代码：

#include <iostream>
#include <cstdio>
using namespace std; 
int main()
{
    int T,n,a,t;
    cin>>T;
    while(T--)
    {
        cin>>n;
        a=n;
        t=1;
        n%=10;
        while(a>=1)
        {
            if(a&1)
                t=(t*n)%10;
            n=(n*n)%10;
            a/=2;
        }
        cout<<t<<endl;
    }
    return 0;
}