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Kimberly-Fasbender wants to merge 2 commits intoAda-C11:masterfrom
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@Kimberly-Fasbender Kimberly-Fasbender commented Sep 17, 2019 •
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Hash Table Practice

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Comprehension Questions

Question Answer
Why is a good Hash Function Important? It can mean the difference between a look up time of O(1) - constant, and O(n) - linear!
How can you judge if a hash function is good or not? You can check and see if it spreads similar elements randomly throughout the hash table, or if it clusters them in a close proximity to one another. You can also check to see if it creates a lot of collisions, or if it doesn't resize appropriately when it needs to.
Is there a perfect hash function? If so what is it? Yes, a hash function that maps a list of elements to a hash table with no collisions is considered perfect.
Describe a strategy to handle collisions in a hash table Linear probing - when there is a collision you go to the next bucket and see if it's empty. If it is you place the element there. If it is not, you continue until you find an empty bucket.
Describe a situation where a hash table wouldn't be as useful as a binary search tree Pretty much any time order matters. For instance, if you had a patient record and needed to be able to pull their min and max weights often.
What is one thing that is more clear to you on hash tables now The different strategies for handling collisions!

CheezItMan
CheezItMan reviewed Sep 18, 2019
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Great work! You got the two methods here. Well done!

lib/exercises.rb
# Space Complexity: ?
# This method will return the k most common nums
# in the case of a tie it will select the first occuring num.
# Time Complexity: O(m * n) - where m is the value of k, and n is the length of the list
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Exactly! Well done!

lib/exercises.rb
# Time Complexity: O(m * n log n) - where m is the length of the list, and n is the average length of a word in the list
# Space Complexity: O(n) - where n is the total amount of characters in list

def grouped_anagrams(strings)
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👍

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@Kimberly-Fasbender @CheezItMan