Problem
Given an input string s, reverse the order of the words.
A word is defined as a sequence of non-space characters. The words in s will be separated by at least one space.
Return a string of the words in reverse order concatenated by a single space.
Note that s may contain leading or trailing spaces or multiple spaces between two words. The returned string should only have a single space separating the words. Do not include any extra spaces.
공백으로 구분된 단어의 순서를 반대로 반환하는 문제.
단어 사이, 선행 후행에 여러 개의 공백을 포함할 수 있으나, 반환하는 문자열엔 단어를 구분할 단일 공백만 허용한다.
Example 1:
Input: s = "the sky is blue"
Output: "blue is sky the"Example 2:
Input: s = " hello world "
Output: "world hello"
Explanation: Your reversed string should not contain leading or trailing spaces.
// 선행과 후행 공백을 포함할 수 없습니다.Example 3:
Input: s = "a good example"
Output: "example good a"
Explanation: You need to reduce multiple spaces between two words to a single space in the reversed string.
// 단어 사이 공백을 단일 공백으로 줄어야 합니다.Constraints:
- 1 <= s.length <= 104
- s contains English letters (upper-case and lower-case), digits, and spaces ' '.
- There is at least one word in s.
Follow-up: If the string data type is mutable in your language, can you solve it in-place with O(1) extra space?
Solution
/**
* @param {string} s
* @return {string}
*/
var reverseWords = function(s) {
return s.split(' ').filter(w => w === "" ? false : true).reverse().join(" ")
};