程序代码：

/* Note:Your choice is C IDE */
#include "stdio.h"
void main()
{
    char ch;
    int alph=0,digit=0,empty=0,other=0;
    printf("输入一行字符:");
    ch=getchar();
    while(ch!='\n')
    {
    if(ch>='a'&&ch<='z'||ch>='A'&&ch<='Z')
      alph++;
     else if(ch>='0'&&ch<='9')
      digit++;
      else if (ch==' ')
      empty++;
      else other++;
    }
      printf("字母的个数为%d\n",alph);
      printf("数字的个数为%d\n",digit);
       printf("空格数为%d\n",empty);
        printf("其他字符的个数为%d\n",other);
}