data-structures
Data structures like dicts, lists, and OrderedDict
Learn how to rename a dictionary key in Python using pop(), del, and comprehensions. Preserve order, handle errors, bulk rename, and nested dicts with code examples and best practices for reliable key changes.
Learn how to efficiently clone JavaScript arrays of objects with circular references using structuredClone(). Avoid recursion errors with this production-ready approach.
Learn efficient methods to check if a vector contains a given element in C++. Compare linear search, binary search, and hash-based approaches with time complexity analysis.
Learn to dereference decoded JSON array in Perl, iterate nested data arrays to extract all sent timestamps and displayText values using loops, map, and safe key checks for reliable JSON processing.
Explaining why Java lacks a SortedList interface in its Collections Framework despite having SortedSet and SortedMap. Learn about design rationale and alternatives for maintaining sorted order in Java lists.
Learn the correct way to create a deep copy of Python dictionaries including nested lists. Use copy.deepcopy() to avoid shared references.
Learn what subscriptable means in Python, which built-in types support indexing operations, and how to check if objects support [] syntax with __getitem__.
Learn how to check if a key exists in std::map using find, contains (C++20), count, and fix equal_range errors. Avoid operator[] inserts with code examples and best practices for C++ map lookups.
Learn how to efficiently access the ith column in a NumPy array using slicing like test[:, i]. Get the first column [1, 3, 5] from [[1,2],[3,4],[5,6]]. Fast views, no copying, perfect for large numpy arrays and indexing.
Step-by-step guide to implement undo and redo functionality in a C++ text editor using gap buffer data structure. Beginner tips, code examples, best practices, and performance optimization for efficient editing.
Learn how to add new keys to a Python dictionary using assignment, update(), setdefault(), and merge operators. No dict.add() method—use these efficient idioms for key-value pairs with examples and pitfalls.
Discover the optimal sock pairing algorithm using in-place sorting like heapsort for O(n log n) time under log-space constraints. Compare with hashing, radix methods, and practical tips for 30 pairs. Relates to element distinctness.