🪐 Leetcode DS & Algo Resources

List of some frequently asked DSA questions. Part 1- Array - https://lnkd.in/gnANUg_4 Part 2 Array - https://lnkd.in/gaxuYPev Part 3- LinkedList - https://lnkd.in/gtXpMe_Z Part 4- Linkedlist- https://lnkd.in/gF2rRzvv Part 5 -String - https://lnkd.in/g84JNUAF Part 6- Two pointers- https://lnkd.in/gS77cMZV Part7- Hashing - https://lnkd.in/gcA83MhC Part 8- Greedy -https://lnkd.in/ggyfDY7V Part 9- Recursion - https://lnkd.in/gaesKYMR Part- 10 - Backtracking - https://lnkd.in/g7PugW_w Part -11 - Binary Search- https://lnkd.in/gpcKWV7Z Maintain consistency solve atleast 3-4 problems everyday, don’t lose hope. Happy Coding!🌝

THE BEST ! https://takeuforward.org/interviews/strivers-sde-sheet-top-coding-interview-problems/

𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐀𝐥𝐥 𝐏𝐚𝐭𝐭𝐞𝐫𝐧𝐬. Pattern ->𝟏𝐃 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 1) Climbing Stairs 2) Frog Jump 3) Frog Jump with K 4) Maximum sum of Non-adjacent elements 5) House robber 2 6) Ninja's Training Pattern -> 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐎𝐧 𝐆𝐫𝐢𝐝𝐬 / 𝟐𝐃 1) Grid Unique Paths 2) Unique Paths 3) Minimum path sum in Grid 4) Tringle (Fixed Starting Point and Variable Ending Point) 5) Minimum/Maximum Falling Path Sum 6) Cherry Pickup 2 Pattern -> 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐎𝐧 𝐒𝐮𝐛𝐬𝐞𝐭𝐬 / 𝐒𝐮𝐛𝐬𝐞𝐪𝐮𝐞𝐧𝐜𝐞 1) Subset Sum Equals to Target 2) Partition Equals Subset Sum 3) Partition A subset into 2 subset with minimum absolute sum diff. 4) Count Subsets With Sum K 5) Count Partitions with given difference 6) 0/1 Knapsack 7) Minimum Coins 8) Target Sum 9) Coin Change 2 10) Unbounded Knapsack 1 D array 11) Rod Cutting 1 D array Pattern -> 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐎𝐧 𝐒𝐭𝐫𝐢𝐧𝐠𝐬 1) Print Length Of Longest Common Subsequence 2) Print Longest Common Subsequence 3) Longest Palindromic Subsequence 4) Minimum Insertion to Make String Palindrome 5) Minimum Insertions/Deletions to Convert String A -> B 6) Shortest Common SuperSequence 7) Distinct Subsequence 8) Edit Distance 9) Wildcard Matching Pattern -> 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐎𝐧 𝐒𝐭𝐨𝐜𝐤𝐬 1) Best Time To Buy and Sell Stock (Buy Ones & Sell Ones ) 1) Best Time To Buy and Sell Stock 2 (Unlimited Time Buy & Sell) 1) Best Time To Buy and Sell Stock 3 ( At Max 2 Times Buy & Sell) 1) Best Time To Buy and Sell Stock 4 (K times Buy & Sell ) 1) Best Time To Buy and Sell Stock 5 (Buy & Sell With Cooldown) 1) Best Time To Buy and Sell Stock 6 (Buy & Sell With Extra Fee) Pattern -> 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐎𝐧 𝐋𝐨𝐧𝐠𝐞𝐬𝐭 𝐈𝐧𝐜𝐫𝐞𝐚𝐬𝐢𝐧𝐠 𝐒𝐮𝐛𝐬𝐞𝐪𝐮𝐞𝐧𝐜𝐞 (LIS) 1) Print Length Of Longest Increasing Subsequence 2) Print Longest Increasing Subsequence 3) Largest Divisible Subset 4) Longest String chain 5) Longest Bitonic Subsequence 6) Number Of Longest Increasing Subsequence Pattern -> 𝐇𝐚𝐫𝐝𝐞𝐬𝐭 𝐃𝐲𝐧𝐚𝐦𝐢𝐜 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐎𝐧 𝐩𝐚𝐫𝐭𝐢𝐭𝐢𝐨𝐧 1) Matrix Chain Multiplication 2) Minimum Cost To cut The Stick 3) Burst Balloons 4) Evaluate Boolean 5) Palindrome Partitioning 2 6) Partition Array For Maximum Sum 7) Maximum Rectangle Area with all 1's (Dp on Rectangle) 8) Count Square Submatrices with all ones (Dp on Rectangle)

Complete JAVA Resources. https://drive.google.com/drive/folders/1IP7B7lhrRq6et72RGUVeLibe8yfvnq9i

Especially to crack Amazon. https://docs.google.com/document/d/1FSa4mtlmk-2KMS7VniZ3_YjlbXL12QWbuLgVJQduHhY/mobilebasic

𝐆𝐑𝐀𝐏𝐇 𝐃𝐚𝐭𝐚𝐒𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐞 𝐑𝐨𝐚𝐝𝐌𝐚𝐩! Day 1 Understand Graphs Understand all three Graph representations and do hands-on - Edge list - Adjacency Matrix - Adjacency List Read and Understand Different Types of Graphs -- Directed Graphs -- Weighted Graphs etc Day 2 Breadth-first search (BFS) Depth-first search (DFS) Day 3 Dijkstra - The shorter path from a given node to all vertices Floyd Warshall - The shorter path from every vertex to every other vertex Day 4 Prims - Minimum spanning tree Kruskal - Minimum spanning tree Day 5 Topological sort Articulation points in a graph Bridges in a graph Johnsons algorithm Day 6 Clone Graph - Leetcode 133 Number of Islands -- Leetcode 200 Course Schedule -- Leetcode 207 Day 7 Valid path -- Leetcode 1391 Is Graph Bipartite? -- Leetcode 785 Smallest multiple with 0 & 1 Day 8 Commutable islands Detect cycle in Directed and Undirected Graph Black shapes Day 9 Knight on chessboard Word ladder I Word ladder II Day 10 Smallest sequence with given primes Capture regions on board Word search board

Important Graph Algos: DFS/BFS Topology sort (Kahn's Algorithm) Cycle detection techniques Component of graphs Bipartite Kruskal algorithm (Minimum spanning tree) Dijkstra algorithm (will not work for negative cycle) Bellman's ford Algorithm Floyd's warshall algorithm Prim's Algorithm Advance Graph Theory Tarjan Algorithm

Some more. Data structures in real-time applications. 𝐒𝐭𝐚𝐜𝐤: 1) UNDO option 2) Text editor: you push letter by letter to the stack so you erase back. 3) Recursion(inbuilt stack) 𝐐𝐮𝐞𝐮𝐞: 1) Your browser deletes the history past one month. 2) If you delete a picture on your phone, it will be the "recently delete" folder which says "the images will be deleted permanently after one week". Here all the images are stored in the queue so it's easier to pop from the rear based on the image deletion date. 3) Waiting list: during online registrations, sometimes you'll be put on the waiting list. basically, all the requests will be stored in the queue. 𝐋𝐢𝐧𝐤𝐞𝐝 𝐥𝐢𝐬𝐭: 1) Browser's Next and Previous Button: a linked list of URLs 2) music player where you can play the next or previous song. (Doubly linked list). 3) In the ludo game, It has to pass the chance to each player in a circular fashion (circular linked list). 𝐓𝐫𝐞𝐞𝐬: 1) File system: Folders and subfolders (N-ary tree). 2) e-commerce websites : category -> subcategories -> products 3) Auto-suggestion when you google (Trie) 𝐆𝐫𝐚𝐩𝐡𝐬: 1) Uber, Ola cab booking: show nearest available cars (BFS) 2) Maven dependencies build order ( Topological sorting (DFS)) 3) While booking bus/flights, you get a list of available routes. 4) In Facebook, users are considered to be the vertices and if they are friends then there is an edge running between them. Facebook’s Friend suggestion algorithm uses graph theory. Facebook is an example of an undirected graph.

𝐓𝐑𝐄𝐄 𝐃𝐚𝐭𝐚 𝐒𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐞 𝐑𝐨𝐚𝐝𝐌𝐚𝐩 Day 1 Read the theory of Binary Trees and different types of Binary Trees Understand the Node structure of Binary Tree Understand and Write Iterative code for following Level Order Traversal Inorder Traversal - Leetcode 194 Preorder Traversal Postorder Traversal Zig Zag Level Oder Traversal Day 2 Implement Binary Tree Add Node Remove Node Traverse Node Construct Binary Tree from Inorder and PostOrder - Leetcode 105 Day 3 Same Tree - Leetcode 100 Invert Binary Tree - Leetcode 226 Symmetric Binary Tree - Leetcode 101 Left/Bottom/Top View of Binary Tree Vertical Order Traversal of a Binary Tree - Leetcode 987 Day 4 Maximum Width of Binary Tree - Leetcode 622 Maximum Depth of Binary Tree - Leetcode 104 Diameter of Binary Tree - Leetcode 543 Balanced Binary Tree - Leetcode 110 Lowest Common Ancestor of a Binary Tree - Leetcode 236 Day 5 Identify Path to given Node Binary Tree Maximum Path Sum - Leetcode 124 Flatten Binary Tree to Linked List - Leetcode 1114 Mirror Binary Tree Serialize and Deserialize Binary Tree - Leetcode 297 Vertical Sum of Nodes in Binary Tree Day 6 Understand Binary Search Tree Search an Element in BST - Leetcode 700 Understand the Complexity of searching in BST Lowest Common Ancestor of a given node in BST - Leetcode 235 Convert Sorted Array to Binary Search Tree - Leetcode 108 Validate Binary Search Tree - Leetcode 98 Day 7 Construct BST from Preorder Traversal - Leetcode 1008 Recover BST - Leetcode 99 Identify Predecessor and Successor of of a Node in BST Kth Smallest Element in a BST Two Sum - Input is BST - Leetcode 653 Day 8 Understand Self-Balancing Binary Search Trees Read and Understand Red Black Tree Read and Understand AVL Tree Day 9 Understand Quadtrees and N-Ary Trees Understand Trie Data Structure Implement Trie (Prefix Tree) Day 10 Maximum XOR of Two Numbers in an Array - Leetcode 421 Maximum XOR With an Element From Array - Leetcode 1707 Hotel Reviews - InterviewBit