Reverse Words in a String

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: "hello world" 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. ```