Find Smallest Letter Greater Than Target

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 lexicogrpahically greater than 'a' in letters is 'c'.

Example 2:

Input: letters = ["c","f","j"], target = "c"
Output: "f"
Explanation: The smallest character that is lexicogrpahically 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.

 class Solution:
    def nextGreatestLetter(self, letters: List[str], target: str) -> str:


#         found = False

#         for char in letters:
#             if char == target:
#                 found = True
#             elif ord(char)>ord(target):
#                 return char
#             if found and char != target:
#                 return char

#         return letters[0]


        for char in letters:
            if char > target:
                return char
        return letters[0]

Find Smallest Letter Greater Than Target

Random Note