Reverse Words While Preserving Spaces

Implement a C++ function that reverses the order of words in a string. Assume a word is any maximal sequence of non-space characters, and the input contains only the space character `' '` as whitespace. **Part 1:** Return the words in reverse order, with leading and trailing spaces removed and exactly one space between adjacent words in the result. **Part 2 (follow-up):** Modify the solution so that the original pattern of space blocks is preserved exactly. That means the lengths of the leading spaces, the spaces between word slots, and the trailing spaces must stay the same; only the word tokens should be reversed. Example: - Input: `" hello world again "` - Part 1 output: `"again world hello"` - Part 2 output: `" again world hello "` Also be prepared to: - write several edge-case test cases, - analyze the time and space complexity of your approach, - and discuss how to optimize the implementation.