[leetCode/JS] 151. Reverse Words in a String

문제 설명

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.

 

입출력 예

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.

 

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.

 

Constraints

• 1 <= s.length <= \(10^4\)
• 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?

---

내 솔루션

/**
 * @param {string} s
 * @return {string}
 */
var reverseWords = function(s) {
  return s.split(' ').filter((w)=>w).reverse().join(' ')
};

// js array reverse 함수.
var reverseArr = function(array) {
  const reArr = [];
  for (let i = array.length-1; i >= 0; i--) {
    reArr.push(array[i])
  }
  return reArr;
}

감상평

• JS라서 매우 쉬웠다. 휴우