Reverse Words in a String: C++ Solution with Two Pointers

This is a solution to the 'Reverse Words in a String' problem on LeetCode (https://leetcode.com/problems/reverse-words-in-a-string/).

The problem asks to reverse the order of the words in a given string and remove any extra spaces between them.

The solution uses a two-pointer approach to traverse the string from right to left. The variable 'i' starts at the end of the string and moves left until it reaches the beginning. The inner loop skips any trailing spaces and moves 'i' to the end of the current word. The variable 'right' stores the index of the last character of the current word.

Once the end of a word is found, the substring from 'i+1' to 'right' is added to the answer string, followed by a single space. This process is repeated until all the words in the string have been processed.

Finally, the answer string is returned without the trailing space at the end.

Overall, the time complexity of this solution is O(n), where 'n' is the length of the input string, since we traverse the string only once. The space complexity is also O(n), since we store the answer string.