Given a list of sorted characters letters
containing only lowercase letters, and given a target letter target
, find the smallest element in the list that is larger than the given target.
Letters also wrap around. For example, if the target is target = 'z'
and letters = ['a', 'b']
, the answer is 'a'
.
Examples:
Input: letters = ["c", "f", "j"] target = "a" Output: "c" Input: letters = ["c", "f", "j"] target = "c" Output: "f" Input: letters = ["c", "f", "j"] target = "d" Output: "f" Input: letters = ["c", "f", "j"] target = "g" Output: "j" Input: letters = ["c", "f", "j"] target = "j" Output: "c" Input: letters = ["c", "f", "j"] target = "k" Output: "c"
Note:
letters
has a length in range[2, 10000]
.letters
consists of lowercase letters, and contains at least 2 unique letters.target
is a lowercase letter.
题意
Solution1
code
1 class Solution { 2 public char nextGreatestLetter(char[] letters, char target) { 3 4 if (letters[0] > target) return letters[0]; 5 if (letters[letters.length - 1] <= target) return letters[0]; 6 7 int left = 0; 8 int right = letters.length - 1; 9 while (left <= right) { 10 int mid = left + (right - left) / 2; 11 if (letters[mid] <= target) { 12 left = mid + 1; 13 } 14 else if (letters[mid] > target) { 15 right = mid - 1; 16 } 17 } 18 return letters[left]; 19 } 20 }