HDU1042(大数运算)

N!

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 41734    Accepted Submission(s): 11606

Problem Description

Given an integer N(0 ≤ N ≤ 10000),your task is to calculate N!

 

 

Input

One N in one line,process to the end of file.

 

 

Output

For each N,output N! in one line.

 

 

Sample Input

  
  

   
   1
2
3
  
  

 

 

Sample Output

  
  

   
   1
2
6
  
  

 

//开辟数组每位存储一个数位，一次用当前数和每一位相乘，注意进位！

#include<iostream>
using namespace std;
#include<stdio.h>
const int SUB=40000;
int main()
{
    int n,i,j;
    int a[SUB];
    int digit;
    int carry;
    int temp;
    while(scanf("%d",&n)!=EOF)
    {
        a[0]=1;
        digit=1;
        if(n==0||n==1)
        {
            printf("%d\n",a[0]);
            continue;
        }
        for(i=2;i<=n;i++)
        {
            for(j=0,carry=0;j<digit;j++)
            {
                temp=a[j]*i+carry;
                a[j]=temp%10;
                carry=temp/10;
            }
            if(carry)
            {
                while(carry)
                {
                    a[j++]=carry%10;
                    carry/=10;
                    digit=j;
                }
            }
        }
        for(i=digit-1;i>=0;i--)
        {
            printf("%d",a[i]);
        }
        printf("\n");
    }
    return 0;
}