BigOSlate Tutorial Library

Explore Interactive Engineering Tutorials

Pick any standalone tutorial below to learn a specific data structure, algorithm, or system concept with plain-English analogies, interactive visual steppers, and 4-language code. Want a structured goal-based study plan instead? Explore our Goal Roadmaps →

Looking for a guided path?
Crack Product-Company Coding Interviews

Follow these 23 tutorials in strict dependency order with live progress tracking.

Open DSA Mastery Roadmap

Data Structures & Algorithms Tutorials

LIVE · 23 TUTORIALS

Self-contained visual tutorials with interactive dry-run steppers, Python/C++/Java/JS code, and curated practice problems.

Core Foundations & Patterns~6h read

Arrays, Memory & In-Place Matrix Operations

Start from zero: learn what an Array actually is in computer memory, why reading is instant while shifting is slow, and how to manipulate arrays and 2D matrices in place.

In-Place Index Marking / Cyclic Sort
4 practice examplesRead Tutorial
Core Foundations & Patterns~6h read

Hashing (Hash Sets & Hash Maps)

Understand what a Hash Function is, how Hash Sets and Hash Maps give instant O(1) value lookups, and how to turn slow O(N^2) searches into single-pass solutions.

Frequency Map / Hash Set Lookup
9 practice examplesRead Tutorial
Core Foundations & Patterns~6h read

Prefix Sums & Kadane's Subarray Algorithm

Learn what a contiguous subarray is, how Prefix Sums answer any range sum in O(1), and how Kadane's Algorithm finds the maximum subarray sum in one pass.

1D & 2D Prefix SumsKadane's Subarray Accumulation
9 practice examplesRead Tutorial
Core Foundations & Patterns~10h read

Two Pointers

Understand what a Pointer index is, why Two Pointers eliminates O(N^2) nested loops using O(1) memory, and master opposite-end, read/write, and 3-way pointers.

Opposite-End Converging PointersSame-Direction Read/Write PointersThree-Way Partitioning (Dutch National Flag)
18 practice examplesRead Tutorial
Core Foundations & Patterns~10h read

Sliding Window

Learn what a Sliding Window is, why re-scanning overlapping subarrays wastes work, and master fixed, variable, and frequency-counted windows.

Fixed-Size Sliding WindowVariable-Size Sliding WindowString Frequency / Anagram Window
5 practice examplesRead Tutorial
Core Foundations & Patterns~14h read

Binary Search (1D, 2D & Answer Space)

Understand what Binary Search is, why cutting a search space in half turns 1 billion steps into 30, and master Exact, Rotated, and Answer-Space Binary Search.

Standard & Boundary Binary SearchRotated & Peak Array SearchBinary Search on Answer Space
5 practice examplesRead Tutorial
Data Structures~14h read

Linked Lists & LRU Cache

Understand what a Node is, why Linked Lists exist compared to Arrays, how to rewire pointers without losing the list, and how to build an LRU Cache.

In-Place Pointer ReversalDummy Sentinel NodeFast & Slow Pointers (Cycle & Middle)
5 practice examplesRead Tutorial
Data Structures~7h read

Stacks (LIFO) & Queues (FIFO)

Learn what Stacks and Queues are from scratch, why restricting access to LIFO or FIFO makes code cleaner and faster, and how to solve bracket and Min-Stack problems.

LIFO Matching & Expression Parsing
2 practice examplesRead Tutorial
Data Structures~8h read

Monotonic Stack & Monotonic Deque

Understand what 'Monotonic' means, why keeping a stack sorted turns O(N^2) 'next greater' searches into O(N), and how a Monotonic Deque tracks window maximums.

Monotonic Increasing / Decreasing StackMonotonic Deque (Sliding Window Max)
3 practice examplesRead Tutorial
Algorithms & Optimization~8h read

Recursion Fundamentals & Subsets

Understand how Recursion and the Call Stack actually work, why Backtracking needs an 'Undo' step, and how to generate all 2^N Subsets.

Subsets (Pick or Skip)
1 practice examplesRead Tutorial
Algorithms & Optimization~10h read

Combinations, Permutations & Grid Backtracking

Master the difference between Combinations (order doesn't matter) and Permutations (order matters), plus 2D Grid Backtracking for Word Search and N-Queens.

Combinations & Duplicate SkippingPermutations & Grid Search
4 practice examplesRead Tutorial
Data Structures~11h read

Binary Trees (DFS, BFS & Bottom-Up Recursion)

Learn what a Binary Tree is from scratch, master Preorder/Inorder/Postorder DFS and Level-Order BFS, and solve Height, Diameter, and LCA problems.

DFS Traversals & Bottom-Up RecursionLevel-Order BFS (Queue)Lowest Common Ancestor (LCA)
4 practice examplesRead Tutorial
Data Structures~7h read

Binary Search Trees (BST)

Understand what makes a Binary Tree a Binary Search Tree (BST), why it gives O(log N) search AND insertion, and how to validate and query BSTs.

Binary Search Tree (BST) Invariant
1 practice examplesRead Tutorial
Data Structures~8h read

Heaps & Priority Queues (Top-K & Two Heaps)

Understand what a Binary Heap is, how it stores a tree inside a flat array, and how to solve Top-K and Streaming Median problems in O(N log K).

Top-K Elements (Min-Heap of Size K)Two Heaps (Streaming Median)
2 practice examplesRead Tutorial
Data Structures~6h read

Tries (Prefix Trees)

Understand what a Trie (Prefix Tree) is from scratch, why Hash Maps cannot do fast prefix autocomplete, and how to build and search a Trie.

Trie (Prefix Tree)
2 practice examplesRead Tutorial
Algorithms & Optimization~6h read

Intervals (Sorting, Merging & Sweep Line)

Understand what an Interval is, why sorting by start time or end time is the universal first step, and how to merge or remove overlapping intervals.

Sort by Start Time (Merge / Insert Intervals)Sort by End Time (Activity Selection)
3 practice examplesRead Tutorial
Algorithms & Optimization~6h read

Greedy Algorithms

Understand what a Greedy Algorithm is, when making the best local choice guarantees the global best answer, and when you must use DP instead.

Local Greedy Reachability (Jump Game)
2 practice examplesRead Tutorial
Algorithms & Optimization~8h read

Graph Fundamentals, BFS & DFS

Understand what a Graph is (Vertices, Edges, Directed/Undirected), how to build an Adjacency List, and when to use Graph DFS vs. Multi-Source BFS.

Matrix & Graph BFS / DFS
2 practice examplesRead Tutorial
Algorithms & Optimization~6h read

Topological Sort & Directed Cycle Detection

Understand what a Directed Acyclic Graph (DAG) and Indegree are, and how Kahn's Algorithm orders tasks with prerequisites or detects deadlocks.

Topological Sort (Kahn's Algorithm)
1 practice examplesRead Tutorial
Algorithms & Optimization~6h read

Dijkstra's Shortest Path & Disjoint Set Union (Union-Find)

Master Dijkstra's Min-Heap Shortest Path for weighted graphs and Disjoint Set Union (Union-Find) for near-O(1) dynamic connectivity.

Dijkstra's Shortest PathDisjoint Set Union (Union-Find)
2 practice examplesRead Tutorial
Algorithms & Optimization~14h read

1D Linear & Knapsack Dynamic Programming

Master Dynamic Programming for product-company interviews: learn how to spot DP vs. Greedy, the 4-stage Brute-Force → Memoization → Tabulation → O(1) Space blueprint, and 0/1 vs. Unbounded Knapsack.

1D Linear DP0/1 & Unbounded Knapsack
4 practice examplesRead Tutorial
Algorithms & Optimization~14h read

2D Grid, String & Subsequence DP

Master 2D Dynamic Programming for product-company interviews: Grid Path DP, Two-String Alignment (Longest Common Subsequence & Edit Distance), and O(N log N) Longest Increasing Subsequence.

2D Grid & String DPLongest Increasing Subsequence (LIS)
2 practice examplesRead Tutorial
Algorithms & Optimization~8h read

Bit Manipulation

Understand binary numbers and bitwise operators from scratch, and master XOR pair cancellation and Brian Kernighan's n & (n - 1) lowest-bit trick.

XOR Cancellation (x ^ x = 0)Clear Lowest Set Bit (n & (n - 1))
4 practice examplesRead Tutorial
Multi-Subject Tutorial Tracks

More Engineering Tutorial Tracks Coming Soon

BigOSlate is expanding with visual tutorials for System Design, Object-Oriented Design, and Database Internals.

COMING SOON

High-Level System Design (HLD) Tutorials

20 Visual Architecture Tutorials

Standalone tutorials on Load Balancers, Consistent Hashing, Redis Caching, Kafka Streams, Sharding, CAP Theorem, and real system designs.

Planned Tutorials:
• Consistent Hashing & Ring Partitioning
• Caching Strategies (Write-Through vs Write-Back)
• Rate Limiters (Token Bucket & Sliding Log)
• Distributed Message Queues (Kafka vs RabbitMQ)
COMING SOON

Low-Level Design (LLD) & Design Patterns Tutorials

15 Object-Oriented Tutorials

Clear tutorials with UML diagrams and 4-language code for SOLID principles, Creational/Structural/Behavioral GoF patterns, and concurrency.

Planned Tutorials:
• SOLID Principles with Real Code Refactoring
• Factory, Builder, Strategy & Observer Patterns
• Thread-Safe Locks, Semaphores & ReadWriteLocks
• Designing Parking Lot & Splitwise Class Models
COMING SOON

SQL, Indexing & Database Internals Tutorials

14 Storage & Query Tutorials

Visual deep dives into how relational and NoSQL engines store data on disk, traverse B+ Trees, and execute transactions safely.

Planned Tutorials:
• How B+ Tree Indexes Speed Up Lookups
• LSM Trees & SSTables in Write-Heavy Databases
• ACID, MVCC & Transaction Isolation Levels
• Window Functions & Query Execution Plans