23.06.09 Today’s Leetcode

744. Find Smallest Letter Greater Than Target (easy)

class Solution:
    def nextGreatestLetter(self, letters: List[str], target: str) -> str:
        def compare(x, y):
            n1, n2 = len(x), len(y)
            n = max(len(x), len(y))
            for i in range(n):
                a = ord(x[i]) if i < n1 else 0
                b = ord(y[i]) if i < n2 else 0
                if a > b:
                    return 1
                if a < b:
                    return -1
            return 0

        for letter in letters:
            if compare(letter, target) > 0:
                return letter
        return letters[0]