Data Structures

What you'll learn

• ✓Estimate the running time of code with Big-O by counting steps, and explain O(1), O(n), O(log n), and O(n²) growth
• ✓Explain how arrays, dynamic arrays, and strings sit in memory and predict which operations are cheap or expensive
• ✓Implement linked lists, stacks, queues, a chained hash table, a binary search tree, and graph representations from scratch in Python
• ✓Use Python's built-in structures (list, dict, set, deque, heapq) fluently and know the cost of every common operation
• ✓Apply the core scanning and traversal patterns — binary search, two pointers, sliding window, BFS, and DFS — and explain why each meets its cost bound
• ✓Choose the right data structure for a problem by naming the operations it must make fast