LeetCode 520. Detect Capital

Given a word, you need to judge whether the usage of capitals in it is right or not.

We define the usage of capitals in a word to be right when one of the following cases holds:

• All letters in this word are capitals, like “USA”.
• All letters in this word are not capitals, like “leetcode”.
• Only the first letter in this word is capital if it has more than one letter, like “Google”.

Otherwise, we define that this word doesn’t use capitals in a right way.Example 1:

Example 1:

Input: "USA"
Output: True

Example 2:

Input: "FlaG"
Output: False

Note: The input will be a non-empty word consisting of uppercase and lowercase latin letters.

class Solution {// 水题
public:
    bool detectCapitalUse(string word) {
         int cnt=0;
         for(int i=1;i<word.size();i++)
            if(islower(word[i]))
               cnt++;
         if(isupper(word[0])){
            if(cnt==0||cnt==word.size()-1)
                   return true;
         }else{
            if(cnt==word.size()-1)
               return true;
         }
        return false;
    }
};