第三章3-7

#include<stdio.h>
int main(void)
{
 int digit,letter,other;
 char ch;
 int i;
 digit=letter=other=0;
 printf("Enter 10characters:");
 for(i=1;i<=10;i++){
  ch=getchar();
  if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z'))
   letter++;
  else if(ch>='0'&&ch<='9')
   digit++;
  else
   other++;
 }
 printf("letter=%d,digit=%d,other=%d\n",letter,digit,other);

 return 0;
}