Problem description
wHAT DO WE NEED cAPS LOCK FOR?
Caps lock is a computer keyboard key. Pressing it sets an input mode in which typed letters are capital by default. If it is pressed by accident, it leads to accidents like the one we had in the first passage.
Let's consider that a word has been typed with the Caps lock key accidentally switched on, if:
- either it only contains uppercase letters;
- or all letters except for the first one are uppercase.
In this case we should automatically change the case of all letters. For example, the case of the letters that form words "hELLO", "HTTP", "z" should be changed.
Write a program that applies the rule mentioned above. If the rule cannot be applied, the program should leave the word unchanged.
Input
The first line of the input data contains a word consisting of uppercase and lowercase Latin letters. The word's length is from 1 to 100 characters, inclusive.
Output
Print the result of the given word's processing.
Examples
Input
cAPS
Output
Caps
Input
Lock
Output
Lock
解题思路：题目的意思就是给定的字符串如果有这两种情况：①：所有字符都为大写字母；②：除了第一个是小写字母以外，其余都是大写字母，如果满足其中任意一种情况，就修改整个字符串（大写变小写，小写变大写），否则直接输出原字符串，简单水过！
AC代码：
1 #include<bits/stdc++.h> 2 using namespace std; 3 int main(){ 4 char s[105];bool flag; 5 cin>>s; 6 if(s[0]>='A' && s[0]<='Z'){ 7 flag=true; 8 for(int i=1;s[i]!=' ';++i) 9 if(s[i]>='a' && s[i]<='z'){flag=false;break;} 10 if(flag)for(int i=0;s[i]!=' ';++i)s[i]+=32; 11 }else{ 12 flag=true; 13 for(int i=1;s[i]!=' ';++i) 14 if(s[i]>='a' && s[i]<='z'){flag=false;break;} 15 if(flag){ 16 s[0]-=32; 17 for(int i=1;s[i]!=' ';++i)s[i]+=32; 18 } 19 } 20 cout<<s<<endl; 21 return 0; 22 }