1105：字符串的反码

#include<stdio.h>
#include<string.h>
int main()
{
	char s[100];
	while(gets(s)&&strcmp(s,"!"))
	{
		int i,len=strlen(s);
		for(i=0;i<len;++i)
		{
			char ch=s[i];
			if(ch>='a'&&ch<='z')
			{
				s[i]='a'+'z'-ch;
			}
			else if(ch>='A'&&ch<='Z')
			{
				s[i]='A'+'Z'-ch;
			}
		}
		printf("%s\n",s);
	}
	return 0;
}