C和指针之函数之归以字符形式按顺序打印数字的每位数字(递归和非递归)

   

    

     

      

     
     

      

       #include <stdio.h>
      
     
    

     

      

     
     

      

       #include <math.h>
      
     
    

     

      

     
     

      

       //以字符形式按顺序打印数字的每位数字,比如4267，打印4267
      
     
    

     

      

     
     

      

       //递归实现
      
     
    

     

      

     
     

      
 
      
     
    

     

      

     
     

      

       void printf_char(unsigned int value)
      
     
    

     

      

     
     

      

       {
      
     
    

     

      

     
     

      

        unsigned int tmp;
      
     
    

     

      

     
     

      

        tmp = value / 10;
      
     
    

     

      

     
     

      

        if (tmp != 0)
      
     
    

     

      

     
     

      

        printf_char(tmp);
      
     
    

     

      

     
     

      

        putchar(value % 10 + '0');
      
     
    

     

      

     
     

      

       }
      
     
    

     

      

     
     

      
 
      
     
    

     

      

     
     

      

       //非递归实现
      
     
    

     

      

     
     

      

       void printf_char1(unsigned int value)
      
     
    

     

      

     
     

      

       {
      
     
    

     

      

     
     

      

        int len = 0;
      
     
    

     

      

     
     

      

        int value1 = value;
      
     
    

     

      

     
     

      

        //计算长度
      
     
    

     

      

     
     

      

        while (value1 > 0)
      
     
    

     

      

     
     

      

        {
      
     
    

     

      

     
     

      

        ++len;
      
     
    

     

      

     
     

      

        value1 /=  10;
      
     
    

     

      

     
     

      

        }
      
     
    

     

      

     
     

      

        double a = pow(10, 2);
      
     
    

     

      

     
     

      

        printf("len is %d\n", len);
      
     
    

     

      

     
     

      

        //4267 4267 / 1000, 4267 / 100 % 10, 4367 / 10 % 10,
      
     
    

     

      

     
     

      

        for (int i = 1; i <= len; ++i)
      
     
    

     

      

     
     

      

        {
      
     
    

     

      

     
     

      

        double dou = pow(10, len - i);
      
     
    

     

      

     
     

      

        i == 1 ? putchar(value / (int)dou + '0') : putchar(value / (int)dou % 10 + '0');
      
     
    

     

      

     
     

      

        }
      
     
    

     

      

     
     

      

       }
      
     
    

     

      

     
     

      

       
      
     
    

     

      

     
     

      

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