DS Algo Questions

Arrays

• Repeat and Missing Number Array (InterviewBit)
• Find a Repeating and a Missing Number (GeeksforGeeks)
• Find Two Non-Repeating Elements in an Array (GeeksforGeeks)
• Find Maximum Sum Triplets (GeeksforGeeks)
• Stock Buy Sell (GeeksforGeeks)
• Find Maximum Number Possible by Doing at Most K Swaps (GeeksforGeeks)
• Minimum Number of Jumps to Reach End (GeeksforGeeks)
• Longest Increasing Subsequence (LeetCode) (Video Explanation)
• Form the Biggest Number (GeeksforGeeks)
• Search a Word in a 2D Grid (GeeksforGeeks)
• Trapping Rain Water (LeetCode)
• Max Points on a Line (LeetCode)
• Check If Array Pairs Are Divisible by K (LeetCode)
• Merge Intervals (LeetCode)
• Subarray Product Less Than K (LeetCode)
• 3Sum (LeetCode)
• Set Matrix Zeroes (LeetCode)
• Range Sum Query 2D (LeetCode)
• First Missing Positive (LeetCode)
• Top K Frequent Elements (LeetCode)
• Longest Palindromic Substring (LeetCode)
• Sort Colors (LeetCode)
• Maximum Points You Can Obtain from Cards (LeetCode)

Hashing

• 4Sum II (LeetCode)
• Longest Consecutive Sequence (LeetCode)
• LRU Cache (LeetCode)
• Longest Substring with Equal 1s and 0s (GeeksforGeeks)
• Range Module (LeetCode)
• My Calendar I (LeetCode)
• My Calendar II (LeetCode)
• My Calendar III (LeetCode)
• Time-Based Key-Value Store (LeetCode)

Cyclic Sort

• Minimum Number of Swaps Required to Sort an Array (GeeksforGeeks)

Sorting

• Kth Largest Element in an Array (LeetCode)
• Count of Smaller Numbers After Self (LeetCode)
• Reverse Pairs (LeetCode)
• Top K Frequent Elements (LeetCode)

LinkedList

• Partition List (InterviewBit)
• Partition List (LeetCode)
• Palindrome List (InterviewBit)
• Palindrome Linked List (LeetCode)
• List Cycle (InterviewBit)
• Flattening a Linked List (GeeksforGeeks)
• Reverse a List in Groups (GeeksforGeeks)
• Reverse Nodes in K-Group (LeetCode)

String

• Group Anagrams (LeetCode)
• Find the Smallest Window Containing All Characters (GeeksforGeeks)
• Minimum Window Subsequence (LeetCode)
• Longest Substring with at Most K Distinct Characters (LeetCode)

Binary Search

• Allocate Minimum Number of Pages (GeeksforGeeks)
• Woodcutting Made Easy (InterviewBit)
• Kth Smallest Element in a Sorted Matrix (LeetCode)
• Maximum Length Possible by Cutting Woods (GeeksforGeeks)
• Median of Two Sorted Arrays (LeetCode)
• Kth Element in Two Sorted Arrays (GeeksforGeeks)

Heaps & Priority Queues

• Merge K Sorted Linked Lists Using Min-Heap (GeeksforGeeks)
• Merge K Sorted Lists (LeetCode)
• Nearly Sorted Algorithm (GeeksforGeeks)
• Top K Frequent Words (LeetCode)
• Find Median from Data Stream (LeetCode)
• Minimum Cost of Ropes (GeeksforGeeks)
• Sliding Window Median (LeetCode)
• Max Value of Equation (LeetCode)
• Trapping Rain Water II (LeetCode)

Stacks/Queues

• Sliding Window Maximum (GeeksforGeeks)
• Design a Stack That Supports GetMin (GeeksforGeeks)
• Min Stack (LeetCode)
• First Non-Repeating Character in a Stream (InterviewBit)
• Zigzag Tree Traversal (GeeksforGeeks)
• Binary Tree Zigzag Level Order Traversal (LeetCode)
• Sort a Stack Using Recursion (GeeksforGeeks)
• Largest Rectangle in Histogram (LeetCode)
• Maximal Rectangle (LeetCode)
• Max Rectangle in Binary Matrix (InterviewBit)
• Next Greater Element I (LeetCode)
• Valid Parenthesis String (LeetCode)
• Decode String (LeetCode)
• Car Fleet II (LeetCode)

Greedy

• Minimum Number of Platforms Required (GeeksforGeeks)
• Majority Element (GeeksforGeeks)
• Minimize Cash Flow Among Friends (GeeksforGeeks)
• Maximum Number of Overlapping Intervals (GeeksforGeeks)
• Task Scheduler (LeetCode)
• Guess the Word (LeetCode)
• Sentence Screen Fitting (LeetCode)
• Maximum Number of Events That Can Be Attended (LeetCode)
• Queue Reconstruction by Height (LeetCode)
• Random Pick with Blacklist (LeetCode)
• Random Pick with Blacklist - Java Discussion (LeetCode)
• Video Stitching (LeetCode)

Trees

• Check if Array Can Represent Preorder Traversal of BST (GeeksforGeeks)
• 2 Sum Binary Tree (InterviewBit)
• Find a Pair with Given Sum in BST (GeeksforGeeks)
• Two Sum IV - Input is a BST (LeetCode)
• Construct Binary Tree from Postorder and Inorder (GeeksforGeeks)
• Find Minimum Depth of a Binary Tree (GeeksforGeeks)
• Least Common Ancestor (InterviewBit)
• Flatten Binary Tree to Linked List (InterviewBit)
• Flatten Binary Tree to Linked List (LeetCode)
• Sorted Linked List to Balanced BST (GeeksforGeeks)
• Convert Sorted List to Binary Search Tree (LeetCode)
• Inorder Tree Traversal Without Recursion (GeeksforGeeks)
• Symmetric Tree - Tree Mirror Image of Itself (GeeksforGeeks)
• Minimum Iterations to Pass Information in Nodes (GeeksforGeeks)
• Query Ancestor-Descendant Relationship in Tree (GeeksforGeeks)
• Check if a Binary Tree is BST (GeeksforGeeks)
• Print Nodes at Distance K in Binary Tree (GeeksforGeeks)
• Construct BST from Preorder Traversal (GeeksforGeeks)
• Serialize/Deserialize Binary Tree (GeeksforGeeks)
• Shortest Distance Between Two Nodes in BST (GeeksforGeeks)
• Merge Two Binary Trees (InterviewBit)
• Binary Tree Zigzag Level Order Traversal (LeetCode)
• Connect Nodes at Same Level with O(1) Space (GeeksforGeeks)
• Maximum XOR of Two Numbers in an Array (LeetCode)
• Sum of Distances in Tree (LeetCode)
• Find Duplicate Subtrees (LeetCode)
• Binary Search Tree - Delete (GeeksforGeeks)
• Delete Node in a BST (LeetCode)
• Recover Binary Search Tree (LeetCode)
• Smallest Subtree with All the Deepest Nodes (LeetCode)
• Lowest Common Ancestor of Deepest Leaves (LeetCode)

Trie

• Find All Shortest Unique Prefixes to Represent Words (GeeksforGeeks)
• Shortest Unique Prefix (InterviewBit)
• Print All Anagrams Together (GeeksforGeeks)
• Design Search Autocomplete System (LeetCode)

DSU (Disjoint Set Union)

• Accounts Merge (LeetCode)
• Most Stones Removed with Same Row or Column (LeetCode)
• Checking Existence of Edge Length Limited Paths (LeetCode)

Graph

• Diameter of Binary Tree (LeetCode)
• Longest Path in an Undirected Tree (GeeksforGeeks)
• Topological Sorting (GeeksforGeeks)
• Clone an Undirected Graph (GeeksforGeeks)
• Word Ladder I (InterviewBit)
• Word Ladder Length of Shortest Chain (GeeksforGeeks)
• Detect Cycle in an Undirected Graph (GeeksforGeeks)
• Detect Cycle in a Graph (GeeksforGeeks)
• Find Precedence of Characters (GeeksforGeeks)
• Minimum Time for All Oranges to Rot (GeeksforGeeks)
• Graph Coloring - Greedy Algorithm (GeeksforGeeks)
• Snake and Ladder Problem (GeeksforGeeks)
• Dijkstra's Shortest Path Algorithm (GeeksforGeeks)
• 0/1 Matrix (LeetCode)
• Count Vowels Permutation (LeetCode)
• Count Vowels Permutation Discussion (LeetCode)
• Number of Ways to Paint N x 3 Grid (LeetCode)
• Critical Connections in a Network (LeetCode)
• Redundant Connection (LeetCode)
• Longest Increasing Path in a Matrix (LeetCode)
• Course Schedule II (LeetCode)
• Cheapest Flights Within K Stops (LeetCode)
• Path with Minimum Effort (LeetCode)
• String Transforms into Another String (LeetCode)
• Pacific Atlantic Water Flow (LeetCode)
• Path Rectangle Containing Circles (GeeksforGeeks)
• Couples Holding Hands - Java Solution (LeetCode)
• Couples Holding Hands (LeetCode)
• Minimum Cost to Make At Least One Valid Path in a Grid (LeetCode)
• 0-1 BFS Shortest Path in a Binary Graph (GeeksforGeeks)
• Shortest Path Visiting All Nodes (LeetCode)
• Shortest Path with Alternating Colors (LeetCode)
• Steps by Knight (GeeksforGeeks)
• Best Meeting Point (LeetCode)
• Shortest Distance from All Buildings (LeetCode)
• Walls and Gates (LeetCode)
• Confusing Number II (LeetCode)
• The Most Similar Path in a Graph (LeetCode)
• Jump Game IV (LeetCode)
• Loud and Rich (LeetCode)
• Where Will the Ball Fall (LeetCode)
• Count Pairs of Nodes (LeetCode)

DP (Dynamic Programming)

• Longest Palindromic Subsequence (GeeksforGeeks)
• Longest Palindromic Subsequence (LeetCode)
• Champagne Tower (LeetCode)
• Subset Sum Problem (GeeksforGeeks)
• Longest Common Subsequence (InterviewBit)
• Best Time to Buy and Sell Stock III (LeetCode)
• Best Time to Buy and Sell Stock III (YouTube)
• Best Time to Buy and Sell Stock IV (LeetCode)
• Best Time to Buy and Sell Stock IV (YouTube)
• Best Time to Buy and Sell Stock with Cooldown (LeetCode)
• Maximum Product Subarray (LeetCode)
• Decode Ways (LeetCode)
• Word Break II (LeetCode)
• Split Array Largest Sum (LeetCode)
• Perfect Squares (LeetCode)
• Minimum Cost for Tickets (LeetCode)
• Minimum Cost for Tickets Discussion (LeetCode)
• 2 Keys Keyboard (LeetCode)
• Dungeon Game (LeetCode)
• Dungeon Game (YouTube)
• Longest Arithmetic Subsequence (LeetCode)
• Triangle (LeetCode)
• Minimum Number of Refueling Stops (LeetCode)
• Best Time to Buy and Sell Stock with Transaction Fee (LeetCode)
• Encode String with Shortest Length (LeetCode)
• Regular Expression Matching (LeetCode)
• Minimum Swaps to Make Sequences Increasing (LeetCode)
• Stone Game III (LeetCode)
• Maximum Sum of 3 Non-Overlapping Subarrays (LeetCode)
• Burst Balloons (LeetCode)
• Predict the Winner (LeetCode)
• Optimal Strategy for a Game (GeeksforGeeks)
• Palindrome Partitioning (GeeksforGeeks)
• As Far from Land as Possible (LeetCode)
• Russian Doll Envelopes (LeetCode)
• Minimum Number of Removals to Make Mountain Array (LeetCode)
• Binary Tree Cameras (LeetCode)
• Make Array Strictly Increasing (LeetCode)
• Make Array Strictly Increasing Discussion (LeetCode)
• Race Car (LeetCode)
• New 21 Game (LeetCode)
• Cherry Pickup II (LeetCode)
• Cherry Pickup (LeetCode)
• House Robber III (LeetCode)