Memory-Efficient String Algorithm | Dataford Interview Questions

Write a string manipulation algorithm that optimizes memory usage and avoids unnecessary allocations.

Implement reverse_words(chars) for a mutable list of single-character strings. Reverse the order of words in place, normalize whitespace to exactly one space between words, and remove leading or trailing whitespace. Return the same list object after modification. A word is a maximal sequence of non-whitespace characters. Do not use split, join, slicing, or a second character array.

Input and Output

chars is a mutable list of characters. Modify it in place and return it.

Constraints

0 <= len(chars) <= 10^5
Each element of chars is a one-character string
Whitespace is represented only by the space character
The input list must be modified in place
Do not use split, join, slicing for the initial transformation, or a second character array

Function Signature

def reverse_words(chars):

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