Data Structures
Chapters
1. Arrays and Strings
Two-pointer, sliding window, prefix sums.
2. Linked Lists
Reverse, cycle detection, merge.
3. Stacks and Queues
Monotonic stack, deque, applications.
4. Trees and Tries
BST, traversals, LCA, Trie operations.
5. Graphs
BFS, DFS, topological sort, shortest path.
6. Heaps and Priority Queues
Top-K problems, Dijkstra, scheduling.
7. Hashing
HashMap, HashSet, collision handling, anagrams.