#include<stdio.h>
  int main()
  {
      char ch,sp;
      ch=getchar();
      
      
       if((ch>'A'&&ch<='Z')||(ch>='a'&&ch<'z'))
       printf("%c%c%c",ch-1,ch,ch+1);
       else
         if((ch=='a')||(ch=='A'))
         printf("%c%c%c",ch+25,ch,ch+1);
         else
            if((ch=='z')||(ch=='Z'))
            
            printf("%c%c%c",ch-1,ch,ch-25);
            else
            printf("%c",ch);
      return 0;      
      
      
  }



为什么我输入大写Z，得到的结果是YZ[呢？

应该不是加减法的问题

Z+1怎么会是A呢

#include<stdio.h>
  int main()
  {
      char ch,sp;
      ch=getchar();
      
      
       if((ch>'A'&&ch<'Z')||(ch>'a'&&ch<'z'))
       printf("%c%c%c",ch-1,ch,ch+1);
       else
         if((ch=='a')||(ch=='A'))
         printf("%c%c%c",ch+25,ch,ch+1);
         else
            if((ch=='z')||(ch=='Z'))
            
            printf("%c%c%c",ch-1,ch,ch-25);
            else
            printf("%c",ch);
      return 0;      
      
      
  }

你在试下

谢谢大家提醒，我犯了一个超级低级错误，if((ch>'A'&&ch<='Z')||(ch>='a'&&ch<'z'))中两个“=”要去掉，下次我会注意的