Implement Stack (LIFO)/Queue (FIFO) in Python (array, linked-list, two-stack) with O(1) ops; validate balanced brackets/RNA dot-bracket notation. Use for stack/queue from scratch, backing BFS/DFS, or checking parens.
Implement Stack (LIFO)/Queue (FIFO) in Python (array, linked-list, two-stack) with O(1) ops; validate balanced brackets/RNA dot-bracket notation. Use for stack/queue from scratch, backing BFS/DFS, or checking parens.