data-structures-and-algorithms

Code Challenge / hashmap_repeated_word

arguments: string

Whiteboard Process

Approach & Efficiency

Function repeated_word(string) finds the first repeated word using a custom hash table.

Approach:

Preprocess input: Remove commas and convert to lowercase. Split string into words. Use a hash table to track word occurrences. Iterate through words, returning the first repeated word. If no repeat found, return None.

Efficiency:

Time complexity: O(N + M), where N is string length and M is word count. Space complexity: O(M) due to the hash table.

Solution

``` def repeated_word(string): ‘’’ A function that finds the first word to occur more than once in a string Arguments: string Return: string ‘’’

words = string.replace(",","").lower().split()

word_table = HashTable()
for word in words:
    if word_table.has(word):
        return word
    word_table.set(word, 1)
return None
        ```