Learning
Interactive lessons with multiple choice, fill-in-the-blank, ordering, matching, and more. Each topic shuffles questions and tracks your score.
Big-O, Big-Θ, Big-Ω, time/space complexity, asymptotic growth.
Base cases, recursive cases, recurrence relations, tail calls.
Singly, doubly, circular lists. Insertion, deletion, traversal.
LIFO, FIFO, deques, applications, array vs. linked-list backing.
Binary trees, traversals (pre/in/post-order), tree properties.
BST property, insertion, deletion, in-order traversal yields sorted.
AVL trees, red-black trees, rotations, balance factors.
Min-heap, max-heap, heapify, priority queues, heapsort.
Hash functions, collisions, chaining, open addressing, load factor.
Set ADT, union-find, disjoint sets, hash sets vs. tree sets.
Quicksort, mergesort, heapsort, comparison vs. non-comparison.
Divide and conquer, merge step, recurrence T(n)=2T(n/2)+n.
Bucket-based, digit-by-digit, LSD vs. MSD, O(nk) time.
Adjacency list/matrix, BFS, DFS, directed/undirected, weighted.
Dijkstra, Bellman-Ford, Floyd-Warshall, A*.
Minimum spanning tree, Prim's, Kruskal's, cut property.