C语言 递归求阶乘和

#include <stdio.h>

double&nbsp;fact(int&nbsp;n)&nbsp;{
  if&nbsp;(n&nbsp;&gt;&nbsp;0)&nbsp;{
    return&nbsp;n&nbsp;*&nbsp;fact(n&nbsp;-&nbsp;1);
  }
  else&nbsp;{
    return&nbsp;1;
  }
}

double&nbsp;factsum(int&nbsp;n)&nbsp;{
  int&nbsp;i;
  int&nbsp;sum&nbsp;=&nbsp;0;

  if&nbsp;(n&nbsp;&gt;&nbsp;0)&nbsp;{
    for&nbsp;(i&nbsp;=&nbsp;1;&nbsp;i&nbsp;&lt;=&nbsp;n;&nbsp;i++)&nbsp;{
      sum&nbsp;+=&nbsp;fact(i);
    }
  }
  
  return&nbsp;sum;
}

int&nbsp;main(){
  int&nbsp;n;
  
  puts(&quot;请输入整数：&quot;);&nbsp;
  scanf(&quot;%d&quot;,&nbsp;&amp;n);
  printf(&quot;fact(%d)&nbsp;=&nbsp;%.0f\n&quot;,&nbsp;n,&nbsp;fact(n));
  printf(&quot;sum&nbsp;=&nbsp;%.0f\n&quot;,&nbsp;factsum(n));

  return&nbsp;0;
}

运行结果：