HDU-1018 Big Number

### 题目：

### description：

In many applications very large integers numbers are required. Some of these applications are using keys for secure transmission of data, encryption, etc. In this problem you are given a number, you have to determine the number of digits in the factorial of the number.

### Input：

Input consists of several lines of integer numbers. The first line contains an integer n, which is the number of cases to be tested, followed by n lines, one integer 1 ≤ n ≤ 107 on each line.

### Output：

The output contains the number of digits in the factorial of the integers appearing in the input.

### Sample Input

### Sample Output

### 解析：

#### 1\. 本题题意，求阶乘结果的位数

#### 2\. 本题其实就是一个数学公式解决。斯特林公式：lnN!=NlnN-N+0.5*ln(2*N*pi)

#### 3\. [百度百科链接][1]

#include<stdio.h>
    #include<math.h>
    #define pi 3.1415926
    int main()
    {
        int ans,i,t,n;
        scanf("%d",&t);
        while(t--)
        {
            scanf("%d",&n);
            ans=(n*log(n)-n+0.5*log(2*n*pi))/log(10);
            ans+=1;
            printf("%d\n",ans);
        }
        return 0;
    }

[1]: https://baike.baidu.com/item/%E6%96%AF%E7%89%B9%E6%9E%97%E5%85%AC%E5%BC%8F/9583086?fr=aladdin