Data Structures & Algorithms
— in Plain English
Learn DSA from scratch with beginner-friendly explanations, hands-on practice problems — and an AI Tutor that explains every problem in plain English, step by step, on demand.
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Validate Binary Search Tree
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Explore Data Structures (Free)
Arrays
A row of lockers for your data
Linked List
Connected nodes forming a chain
Stacks
Last In First Out structure
Queues
First In First Out structure
HashMap & HashSet
Fast lookup using keys
Binary Trees
Hierarchical node-based structure
Heaps
Priority-based tree structure
Graphs (BFS/DFS)
Nodes connected with edges
AVL Trees
Self-balancing binary search trees
Tries
Prefix-based word lookup tree
Segment Trees
Range queries and updates in O(log n)
Union-Find (DSU)
Track connected components efficiently
Explore Algorithms (Free)
Sorting Algorithms
Arrange data in order
Search Algorithms
Find items efficiently
String Manipulation
Transform and analyze text
Advanced Graph Algorithms
Shortest paths and connectivity
Dynamic Programming
Break problems into overlapping subproblems
Two Pointers
Two indices moving through data in tandem
Sliding Window
Maintain a moving subarray over data
Backtracking
Explore all possibilities, prune dead ends
Greedy Algorithms
Make the locally optimal choice at each step
Bit Manipulation
Operate directly on binary representations
Recursion & Divide and Conquer
Split problems, solve halves, combine results
Matrix & 2D Arrays
Grid traversal, rotation, and DP on 2D
Intervals
Merge, insert and count overlapping ranges