HDU1042 N!(大整数类应用)

#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <ctype.h>


using namespace std;


int a[50000];

int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        int i,j,carry,len=1,t;
        memset(a,0,sizeof(a));
        a[0]=1;

        for(i=2;i<=n;i++)
        {
            for(carry=0,j=0;j<len;j++)
            {
                t=a[j]*i+carry;
                a[j]=t%10;
                carry=t/10;
            }
            while(carry)
            {
                a[j++]=carry%10;
                carry/=10;
                len++;
            }
        }
        for(j=len-1;j>=0;j--)
            printf("%d",a[j]);
        printf("\n");
    }
    return 0;
}