Linked Lists, Stacks, and Queues Questions

Pointer-based linear structures and the classic problems built on them: singly, doubly and circular linked lists (reversal whole, partial and in groups of k, cycle detection and cycle start with fast/slow pointers, intersection, middle and nth-from-end, merging two or k sorted lists, sorting a list, reordering, palindrome check, rotation, partitioning, duplicate removal, deep copy with random pointers, flattening child lists, sentinel nodes), implementing lists in C, C++ and Rust with attention to pointer handling, ownership and cleanup, array versus linked-list trade-offs including cache locality, stacks, queues and deques (array, linked and circular-buffer implementations, ring-buffer full versus empty, queue from two stacks, min stack, round-robin scheduling), monotonic stacks and queues (next greater element, largest rectangle in a histogram, sliding-window maximum), stack-based expression and bracket evaluation (balanced brackets, Reverse Polish Notation, infix to postfix, calculators), and structure-level builds such as an LRU cache from a hash map plus doubly linked list, undo/redo history, and variants like persistent or unrolled lists. Foundational for coding interviews and for understanding how higher-level structures are built. Concurrent and lock-free queues, memory allocators, general graph traversal, heaps and cache-eviction system design are covered elsewhere.