C语言习题2

计算 1!+2!+3!+......+10!

思路1:单循环

#include <stdio.h>

int main()
{
  int i = 0;
  int jie = 1;
  int sum = 0;
  for(i=1;i<=10;i++)
  {
    jie = jie * i;
    sum = sum + jie;
  }
  printf("1!+2!+...+10!=%d\n",sum);
  return 0;                          
}

思路2: 嵌套双循环

#include <stdio.h>                  
                                    
int main()                          
{                                   
  int i = 0;                        
  int n = 0;                        
  //定义一个变量求n!                
  int danjie = 1;                   
  int sum = 0;                      
  for(i=1;i<=10;i++)                
  {                                 
    danjie = 1;                     
    for(n=1;n<=i;n++)               
    {                               
      danjie = danjie * n;          
    }                               
    sum = sum + danjie;             
  }                                 
  printf("1!+2!+...+10!=%d\n",sum); 
  return 0;                         
}