題目：

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:

1. All letters in this word are capitals, like “USA”. 2.All letters in this word are not capitals, like “leetcode”. 3.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:

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.

解釋： 判斷拼寫是否正確 python程式碼：

class Solution(object):
    def detectCapitalUse(self, word):
        """
        :type word: str
        :rtype: bool
        """
 

        if word.isupper():
            return True
        elif word.islower():
            return True
        elif word==word.capitalize():
            return True
        return False                

c++程式碼：

#include <cctype>
class Solution {
public:
    bool detectCapitalUse(string word)
 
 {
        int  cnt=0;
        for (auto c:word)
            if (isupper(c))
                cnt+=1;
        return (cnt==0 ||cnt==word.size() || (cnt==1 && isupper(word[0])));  
    }
};

總結： pythoncapitalize()將字串的第一個字母變成大寫,其他字母變小寫。 python 的 isupper() islower() upper() lower()函式。 c++ <cctype>中的 isupper()函式，toupper()和tolower()在C++中定義分別在std和<cctype>中。 c++中實現大小寫轉換：

#include <iostream>
#include <string>
#include <cctype>
#include <algorithm>
using namespace std;
int main()
{
    string s = "Hello World";
    cout << s << endl;
    transform(s.begin(),s.end(),s.begin(),::toupper);
    cout << s << endl;
    transform(s.begin(),s.end(),s.begin(),::tolower);
    cout << s << endl;
    return 0;
}