编辑代码

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