Difficulty | Runtime | Faster_than | Memory | Lesser_than |
---|---|---|---|---|
easy | 91 ms | 74.25 % | 44.1 mb | 37.32 % |
744. 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 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.
Solution:
var nextGreatestLetter = function(letters, target) {
var l = 0;
var r = letters.length - 1;
if(target >= letters[r]) return letters[0]
while (l < r) {
if(letters[l] < target || letters[l] === target) l++;
if(letters[l] > target) {
return letters[l];
}
}
};