520. Detect capital letters

• Question no ： Power button 520
• Knowledge point ： character string
• Goal completion ：20/150
• summary
  stem ：
  

Ideas ：

• 1. First judge the case of the first letter , If the first letter is lowercase , Then the following must be lowercase , If it appears directly after False
• 2. If the first letter is capitalized , Look at the case of the second letter , If the second letter is lowercase , Then the following must be lowercase , If it appears directly after False
• 3. If the second letter is capitalized , Then the following must be all capitalized , If lowercase appears after it, it directly returns False

#
# @lc app=leetcode.cn id=520 lang=python3
#
# [520]  Detect capital letters 
#

# @lc code=start
class Solution:
    def detectCapitalUse(self, word: str) -> bool:
        a = ord('a')
        z = ord('z')
        A = ord('A')
        Z = ord('Z')
        if len(word) <= 1:
            return True
        if a<=ord(word[0])<=z:
            for i in range(len(word)):
                if A<=ord(word[i])<=Z:
                    return False
            return True
        elif A<=ord(word[0])<=Z:
            if a<=ord(word[1])<=z:
                for j in range(1, len(word)):
                    if A<=ord(word[j])<=Z:
                        return False
                return True
            for l in range(1, len(word)):
                    if a<=ord(word[l])<=z:
                        return False
            return True
# @lc code=end