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 <= 104letters[i]is a lowercase English letter.lettersis sorted in non-decreasing order.letterscontains at least two different characters.targetis 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]