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:

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.

题意：给你一个字符串，判断其是否符合规范

这是我的代码。感觉有点蠢。

class Solution {
public:
    bool detectCapitalUse(string word) {
        if(word[0] >= 65 && word[0] <= 90){
            int n = 0;
            int m = 0;
            for(int i = 1; i < word.size(); i++){
                if(word[i] <= 90)
                    m = 1;
                else
                    n = 1;
            }
            if(n + m > 1)
                return false;
        }
        else{
            for(int i = 1; i < word.size(); i++){
                if(word[i] < 'a')
                    return false;
            }
        }
        return true;
    }
};

还有一个是C++正则表达式做出来的。

class Solution {
public:
    bool detectCapitalUse(string word) {
        return regex_match(word, regex("[A-Z]+|[a-z]+|[A-Z][a-z]*"));
    }
};

Discuss 网友Python答案：

When adding a boolean in python it is changed to a 1 or 0. You can loop through each character and sum the amount of upper case letters seen.

def detectCapitalUse(self, word):
    total = 0
    for c in word:
        total += c.isupper()
    return total == 0 or len(word) == total or (total == 1 and word[0].isupper())
    # return all_lowercase or all_uppercase or only_the_first_is_upper