# Solving Leetcode Interviews in Seconds with AI: Reverse Words in a String


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "151" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like [Chatmagic](https://www.chatmagic.app), we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

	# Problem Statement
	> 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.    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: If the string data type is mutable in your language, can you solve it in-place with O(1) extra space? 

	# Explanation
	Here's an efficient solution to reverse the order of words in a string, addressing the constraints of extra spaces and in-place (if possible) requirements.

*   **Split and Filter:** Split the input string into a list of words, removing leading/trailing spaces and handling multiple spaces between words by filtering out empty strings.
*   **Reverse:** Reverse the order of the words in the list.
*   **Join:** Join the reversed list of words back into a string, using a single space as a separator.

*   **Time Complexity:** O(n), where n is the length of the input string.
*   **Space Complexity:** O(n) due to the creation of a list of words and the final reversed string. If in-place modification were possible in Python strings (which it isn't), the space complexity could be reduced to O(1).

	
	# Code
	```python
	def reverse_words(s):
    """
    Reverses the order of words in a string, handling extra spaces.

    Args:
        s: The input string.

    Returns:
        The string with words reversed and extra spaces removed.
    """
    words = s.split()
    words = [word for word in words if word]  # Remove empty strings (multiple spaces)
    words.reverse()
    return " ".join(words)
	```