LeetCode 2: Add Two Numbers – Step-by-Step Linked List Addition Explained Clearly

Learn How to Add Numbers Represented as Linked Lists Using Carry Logic, Dummy Nodes, and Iterative Traversal (Beginner Friendly Guide)

LeetCode 203: Remove Linked List Elements – Step-by-Step Guide for Beginners

Learn How to Remove Nodes from a Linked List Using Iteration, Edge Case Handling, and Dummy Node Technique (With Clear Intuition)

LeetCode 290: Word Pattern – Multiple Ways to Verify Bijection Between Pattern Characters and Words

Learn How to Solve the Word Pattern Problem Using HashMaps, Bidirectional Mapping, and Index Mapping Techniques

LeetCode 123 — Best Time to Buy and Sell Stock III | At Most Two Transactions Explained

From left-right prefix DP to the elegant four-variable state machine — a complete guide to the hardest constraint in the stock series.

LeetCode 122 — Best Time to Buy and Sell Stock II | Every Approach Explained

From greedy intuition to peak-valley thinking — a complete guide to maximizing stock profit with unlimited transactions.

LeetCode 121 — Best Time to Buy and Sell Stock I | Two Pointer / Sliding Window Explained

A beginner-friendly breakdown of the classic stock profit problem — intuition, dry run, commented Java code, and complexity analysis.

LeetCode 2: Add Two Numbers – Step-by-Step Linked List Addition Explained Clearly

Learn How to Add Numbers Represented as Linked Lists Using Carry Logic, Dummy Nodes, and Iterative Traversal (Beginner Friendly Guide)

LeetCode 203: Remove Linked List Elements – Step-by-Step Guide for Beginners

Learn How to Remove Nodes from a Linked List Using Iteration, Edge Case Handling, and Dummy Node Technique (With Clear Intuition)

LeetCode 290: Word Pattern – Multiple Ways to Verify Bijection Between Pattern Characters and Words

Learn How to Solve the Word Pattern Problem Using HashMaps, Bidirectional Mapping, and Index Mapping Techniques

LeetCode 123 — Best Time to Buy and Sell Stock III | At Most Two Transactions Explained

From left-right prefix DP to the elegant four-variable state machine — a complete guide to the hardest constraint in the stock series.

LeetCode 122 — Best Time to Buy and Sell Stock II | Every Approach Explained

From greedy intuition to peak-valley thinking — a complete guide to maximizing stock profit with unlimited transactions.

LeetCode 121 — Best Time to Buy and Sell Stock I | Two Pointer / Sliding Window Explained

A beginner-friendly breakdown of the classic stock profit problem — intuition, dry run, commented Java code, and complexity analysis.