Leetcode 0744 Find Smallest Letter Greater Than Target

Problem statement

https://leetcode.com/problems/find-smallest-letter-greater-than-target/

Solution

Just perform classical binary search and if we found that answer is equal to n, than we return 0.

Complexity

Time complexity is O(log n), space is O(1).

Code

class Solution:
    def nextGreatestLetter(self, letters, target):
        return letters[bisect.bisect(letters, target) % len(letters)]