大小写能够正常输出字符就有点尴尬了
#include <stdio.h>
void main (void)
{
    int a;
    char ch,sh;

    for (a=0;a<=8;a++)
    {
     scanf("%c",&ch);
        if (ch<='Z'&&ch>='A'||ch<='z'&&ch>='a')
        {
                if (ch<='Z'&&ch>='A')
                {
                     sh='A'+('Z'-ch);
                    printf("%c",sh);
                }
                else if(ch<='z'&&ch>='a')
                {
                    sh='a'+('z'-ch);
                    printf("%c",sh);

                }
                else
                {
                    printf("%c",ch);
                }
                printf("\n");
        }
        
    }
}