151__medium__reverse_words_in_a_string.js

/**
 * @param {string} str
 * @returns {string}
 */

/**
 *
 * O(n) time
 * O(1) space
 *
 */
var reverseWords = function(str) {
  str = str.trim().replace(/\s\s+/g, " ");
  str = str.split(" ");
  let lo = 0;
  let hi = str.length - 1;
  while (lo < hi) {
    [str[lo], str[hi]] = [str[hi], str[lo]];
    lo++;
    hi--;
  }
  return str.join(" ");
};