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. 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. Example 4: Input: s = " Bob Loves Alice " Output: "Alice Loves Bob" Example 5: Input: s = "Alice does not even like bob" Output: "bob like even not does Alice" 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: Could you solve it in-place with O(1) extra space?