http://acm.hdu.edu.cn/showproblem.php?pid=1060

Leftmost Digit

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

Total Submission(s): 7028 Accepted Submission(s): 2703
[/b]

[align=left]Problem Description[/align]
Given a positive integer N, you should output the leftmost digit of N^N.

[align=left]Input[/align]
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).

[align=left]Output[/align]
For each test case, you should output the leftmost digit of N^N.

[align=left]Sample Input[/align]

2
3
4

[align=left]Sample Output[/align]

2
2
AC代码：

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
int T;
cin>>T;
while(T--)
{
long long n;
cin>>n;
double k=n*log10(double(n));
k=k-(long long )k;//注意这里应是1long long 类型
k=pow(10.0,k);
while(k<1)
k*=10;
cout<<(int)k<<endl;
}return 0;
}