n的阶乘

#include<stdio.h>

int fun(int n){
  if(n ==1 || n ==0){
    return 1;
  }
  return n*fun(n-1);
}

int main(int argc,char** argv)
{
  int n;
  scanf("%d",&n);
  printf(“n!=%d\n”,fun(n));
  return 0;
}

结果：