cleanup algs and hash tables

[dchou1618]

User description

Description

hash table practice and tests

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PR Type

Enhancement, Tests

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Description

• Implement RandomizedSet data structure with O(1) insert, remove, and getRandom operations

• Use hash table and list combination for efficient random element retrieval

• Add comprehensive test suite for RandomizedSet functionality

• Remove obsolete num_in_intervals.py file with interval coverage algorithm

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Diagram Walkthrough

flowchart LR
  A["RandomizedSet Class"] --> B["Hash Table + List"]
  B --> C["Insert O(1)"]
  B --> D["Remove O(1)"]
  B --> E["getRandom O(1)"]
  F["Test Suite"] --> A

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File Walkthrough

	Relevant files
Enhancement	hash_table.py RandomizedSet with O(1) operations                                              Algorithms/datastructs/hash_table.py New RandomizedSet class implementing insert, remove, and getRandom operations Uses hash table to store value-to-index mappings and list for random access Swap-with-last technique for O(1) removal without maintaining order Raises IndexError when getRandom is called on empty set +30/-0
Tests	test_hash_table.py RandomizedSet unit tests                                                                  tests/test_hash_table.py Comprehensive test suite for RandomizedSet class Tests insert, remove, and getRandom operations with various scenarios Validates behavior on empty sets and duplicate insertions Includes edge cases like removing non-existent elements +40/-0
Miscellaneous	num_in_intervals.py Remove obsolete interval coverage code                                      Algorithms/datastructs/num_in_intervals.py File completely removed as part of cleanup Contained interval coverage algorithm using sweep line and heap No longer needed in codebase +0/-73

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[qodo-code-review]

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🔴	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Non-descriptive identifier: The new code introduces the abbreviated attribute name lst, which is not self-documenting and reduces readability. Referred Code self.lst = [] def insert(self, val: int) -> bool: Learn more about managing compliance generic rules or creating your own custom rules
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[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Use pytest.raises for exception In test_randomized_set, replace the try/except block with pytest.raises(IndexError) to properly assert that an exception is raised. tests/test_hash_table.py [31-35] -try: +import pytest + +with pytest.raises(IndexError): rs.getRandom() - print("getRandom on empty set did not raise error — consider adding handling for empty set.") -except IndexError: - print("getRandom on empty set raised IndexError as expected.") Apply / Chat Suggestion importance[1-10]: 6 __ Why: The suggestion correctly points out that using pytest.raises is the standard and more robust way to test for exceptions in a pytest suite, making the test more idiomatic and turning a printed message into a proper assertion.	Low
	Simplify removal swap logic Simplify the swap-with-last logic in the remove method by removing a redundant assignment to self.lst[-1]. Algorithms/datastructs/hash_table.py [18-22] if idx != len(self.lst)-1: last = self.lst[-1] - self.lst[-1] = self.lst[idx] self.lst[idx] = last self.hash_table[last] = idx Apply / Chat Suggestion importance[1-10]: 5 __ Why: The suggestion correctly identifies a redundant and confusing assignment (self.lst[-1] = self.lst[idx]) and proposes a cleaner, more direct implementation of the swap logic, which improves code readability and maintainability.	Low
	Use random.choice for getRandom Replace random.randint with random.choice in the getRandom method for improved readability and conciseness when selecting a random element. Algorithms/datastructs/hash_table.py [30] -return self.lst[random.randint(0, len(self.lst) - 1)] +return random.choice(self.lst) Apply / Chat Suggestion importance[1-10]: 4 __ Why: The suggestion correctly proposes using random.choice(self.lst) as a more idiomatic and readable way to select a random element from a list compared to self.lst[random.randint(0, len(self.lst) - 1)].	Low
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