reverse_words_in_string.js

// 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) {
  let stringArray = s
    .trim()
    .split(" ")
    .filter(a => a.length > 0);
  let out = "";
  for (let i = stringArray.length - 1; i >= 0; i--) {
    out += stringArray[i] + (i >= 1 ? " " : "");
  }

  return out;
};

reverseWords("a good   example"); //?