hdu1018

Big Number

                                                          Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
                                                           Total Submission(s): 24633    Accepted Submission(s): 11191

Problem 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

21020

 

Sample Output

719

 

Source

Asia 2002, Dhaka (Bengal)

大数处理分为两种：一 需要用到大数处理方法   二  伪大数处理方法 用一些公式和技巧求得所需值

#include<stdio.h>#include<math.h>int main(){    int t;    scanf("%d",&t);    while(t--)    {        int n;        double sum=0;        scanf("%d",&n);        while(n)        {            sum+=log10(n);            n--;        }        printf("%.f\n",sum+0.5);    }    return 0;}

此题可以用公式  lnN!=NlnN-N+0.5*ln(2*N*pi)