leetcode 744 Find Smallest Letter Greater Than Target 寻找比目标字母大的最小字母 python 多种思路 ord(),chr()

class Solution:
    def nextGreatestLetter(self, letters, target):
        """
        :type letters: List[str]
        :type target: str
        :rtype: str
        """
        # method one   ord()，chr（）函数 ， 没有充分利用letters有序这个条件
        # ascii_target = ord(target)
        # while ascii_target:
        #     ascii_target += 1
        #     if ascii_target > 122:
        #         ascii_target -= 26
        #     if chr(ascii_target) in letters:
        #         return chr(ascii_target)


        # method two 直接比较字符大小(letters有序)
        for letter in letters:
            if letter > target:
                return letter
        return letters[0]