1047 单个字母大小写互换

#include<iostream>
using namespace std;
int main(){
char ch;
cin>>ch;
if(ch>='a'&&ch<='z')
cout<<char(ch-32)<<endl;
else if(ch>='A'&&ch<='Z')
cout<<char(ch+32)<<endl;
else
cout<<ch<<endl;
return 0;
}