- Difficulty: Easy
- Tags: LeetCode, Easy, Array, Binary Search, leetcode-744, O(logn), O(1)
Problem
You are given an array of characters letters
that is sorted in non-decreasing order, and a character target
. There are at least two different characters in letters
.
Return the smallest character in letters
that is lexicographically greater than target
. If such a character does not exist, return the first character in letters
.
Example 1:
Input: letters = ["c","f","j"], target = "a" Output: "c" Explanation: The smallest character that is lexicographically greater than 'a' in letters is 'c'.
Example 2:
Input: letters = ["c","f","j"], target = "c" Output: "f" Explanation: The smallest character that is lexicographically greater than 'c' in letters is 'f'.
Example 3:
Input: letters = ["x","x","y","y"], target = "z" Output: "x" Explanation: There are no characters in letters that is lexicographically greater than 'z' so we return letters[0].
Constraints:
2 <= letters.length <= 104
letters[i]
is a lowercase English letter.letters
is sorted in non-decreasing order.letters
contains at least two different characters.target
is a lowercase English letter.