大数阶乘

#include <stdio.h>
int main()
{
    int carry,n,j;
    int a[40001];
    int digit;
    int temp,i;   
    while(scanf("%d",&n)!=EOF){
    a[0]=1;digit=1;
    for(i=2; i<=n; i++)
    {
        for(carry=0,j=1; j<=digit; ++j)
        {
            temp=a[j-1]*i+carry;
            a[j-1]=temp%10;
            carry=temp/10;
        }
        while(carry)
        {
            digit++;
            a[digit-1]=carry%10;
            carry/=10;
        }
    }
   
    for(int k=digit; k>=1; --k)
        printf("%d",a[k-1]);
    printf("\n");
 printf("length=%d\n",digit);
 }
    return 0;
}