20131001国庆作业第一章例1-1

#include<stdio.h>
int main(void)
{
int n;

int factorial(int n);

scanf("%d",&n);
printf("%d\n",factorial(n));

return 0;
}
int factorial(int n)
{
int i,fact=1;

for(i=1;i<=n;i++)
fact=fact*i;

return fact;
}