feat: Add XOR-based doubly linked list mode for memory efficiency#709
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Sreevarsh-Mahesh wants to merge 1 commit intocodezonediitj:mainfrom
Open
feat: Add XOR-based doubly linked list mode for memory efficiency#709Sreevarsh-Mahesh wants to merge 1 commit intocodezonediitj:mainfrom
Sreevarsh-Mahesh wants to merge 1 commit intocodezonediitj:mainfrom
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Implements issue codezonediitj#692 by adding an optional 'xor' mode to DoublyLinkedList that uses XOR of adjacent node addresses to reduce memory usage from 2 pointers to 1 pointer per node. Features: - Add mode parameter ('standard' or 'xor') to DoublyLinkedList.__new__ - Implement XOR node structure with links=['both'] - Maintain id_to_node dictionary for pointer dereferencing - Refactor all insert/extract methods for XOR mode support - Override __getitem__, __str__, and search for XOR traversal - Maintain full backward compatibility with standard mode Testing: - Add comprehensive test suite for XOR mode - Test parity between standard and XOR modes - Test edge cases (empty, single, large lists) - All 114 existing tests still pass Fixes codezonediitj#692
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References to other Issues or PRs or Relevant literature
Fixes #692
Brief description of what is fixed or changed
This PR implements a memory-efficient XOR-based doubly linked list mode for
DoublyLinkedList.What is XOR Linked List?
An XOR linked list stores a single pointer containing the XOR of adjacent node addresses instead of two separate pointers, reducing memory usage while maintaining bidirectional traversal capability.
Implementation:
modeparameter toDoublyLinkedList.__new__()with options:'standard'(default) or'xor'links=['both']to store XOR of adjacent node IDs_id_to_nodedictionary for node reference tracking (simulates pointer dereferencing in Python)insert_after(),insert_before(),insert_at(),extract()__getitem__(),__str__(), andsearch()for XOR traversal supportTesting:
test_DoublyLinkedList_XOR()- Full feature test matching standard mode behaviortest_DoublyLinkedList_XOR_vs_Standard()- Parity test between modestest_DoublyLinkedList_XOR_EdgeCases()- Edge cases (empty, single, large lists)test_DoublyLinkedList_InvalidMode()- Error handlingUsage Example: