151.reverse-words-in-a-string.js

/*
 * @lc app=leetcode id=151 lang=javascript
 *
 * [151] Reverse Words in a String
 *
 * https://leetcode.com/problems/reverse-words-in-a-string/description/
 *
 * algorithms
 * Medium (16.37%)
 * Total Accepted:    272.4K
 * Total Submissions: 1.7M
 * Testcase Example:  '"the sky is blue"'
 *
 * Given an input string, reverse the string word by word.
 *
 *
 *
 * Example 1:
 *
 *
 * Input: "the sky is blue"
 * Output: "blue is sky the"
 *
 *
 * Example 2:
 *
 *
 * Input: "  hello world!  "
 * Output: "world! hello"
 * Explanation: Your reversed string should not contain leading or trailing
 * spaces.
 *
 *
 * Example 3:
 *
 *
 * Input: "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.
 *
 *
 *
 *
 * Note:
 *
 *
 * A word is defined as a sequence of non-space characters.
 * Input string may contain leading or trailing spaces. However, your reversed
 * string should not contain leading or trailing spaces.
 * You need to reduce multiple spaces between two words to a single space in
 * the reversed string.
 *
 *
 *
 *
 * Follow up:
 *
 * For C programmers, try to solve it in-place in O(1) extra space.
 */
/**
 * @param {string} s
 * @return {string}
 */
var reverseWords = function(s) {
  s = s.trim();
  //if more then one, reduce to one, if one, reduce to one
  //Regex is fast
  s = s.replace(/\s+/g, " ");

  let reverseWords = s.split(" ").reverse();

  return reverseWords.join(" ");
};