DSA Pattern Roadmap (From Zero to Placement Ready) ┣  1. Foundations You Cannot Skip ┃ ┣ Time & Space Complexity ┃ ┣  Big-O Notation ┃ ┣  Recursion Basics ┃ ┣  Basic Math (GCD, Prime, Factorization, Modulo) ┃ ┗  Problem Solving Basics (Brute Force → Better Approach) ┣  2. Core Data Structures ┃ ┣  Arrays ┃ ┣  Strings ┃ ┣  Linked Lists ┃ ┣  Stack ┃ ┣  Queue / Deque ┃ ┣  HashMap / HashSet ┃ ┗  Heap / Priority Queue Basics ┣  3. First Pattern Layer ┃ ┣  Two Pointers ┃ ┣  Sliding Window ┃ ┣  Prefix Sum ┃ ┣  Binary Search on Array ┃ ┣  Sorting + Observation ┃ ┗  Frequency Counting / Hashing Patterns ┣  4. Recursion & Search Patterns ┃ ┣  Recursion on Arrays / Strings ┃ ┣  Backtracking ┃ ┣  Subsets / Subsequences ┃ ┣  Permutations / Combinations ┃ ┣  Decision Tree Thinking ┃ ┗  Pruning Techniques ┣  5. Tree Patterns ┃ ┣  Binary Tree Traversals ┃ ┣  BST Basics ┃ ┣  DFS on Trees ┃ ┣  BFS / Level Order ┃ ┣  Height / Diameter / Balanced Tree ┃ ┣  Path Sum / Tree DP Basics ┃ ┗  Lowest Common Ancestor ┣  6. Graph Patterns ┃ ┣  Graph Representation ┃ ┣  BFS ┃ ┣  DFS ┃ ┣  Connected Components ┃ ┣  Cycle Detection ┃ ┣  Topological Sort ┃ ┣  Shortest Path Basics ┃ ┗  Union Find / Disjoint Set ┣  7. Advanced Pattern Layer ┃ ┣  Monotonic Stack ┃ ┣  Monotonic Queue ┃ ┣  Heap / Top K Problems ┃ ┣  Trie ┃ ┣  Bit Manipulation ┃ ┣  Greedy Patterns ┃ ┣  Interval Problems ┃ ┗  Merge / K-way Processing ┣  8. Dynamic Programming Roadmap ┃ ┣  1D DP ┃ ┣  2D DP ┃ ┣  Take / Not Take Pattern ┃ ┣  Knapsack Variants ┃ ┣  LIS Pattern ┃ ┣  String DP ┃ ┣  Grid DP ┃ ┣  DP on Subsequences ┃ ┣  DP on Trees ┃ ┗  State Design Practice ┣  9. Advanced Algorithms ┃ ┣  Dijkstra’s Algorithm ┃ ┣  Floyd Warshall Basics ┃ ┣  Minimum Spanning Tree ┃ ┣  Kahn’s Algorithm ┃ ┣  Shortest Path Variants ┃ ┣  Binary Search on Answer ┃ ┣  Segment Tree / Fenwick Tree Basics ┃ ┗  Advanced Graph + DP Mix Problems ┣  10. Pattern Recognition Training ┃ ┣  How to Identify the Input Type ┃ ┣  How to Spot Trigger Words ┃ ┣  Map Problem → Pattern ┃ ┣  Brute Force → Optimized Thinking ┃ ┣  Similar Problem Grouping ┃ ┣  Pattern Notes / Cheat Sheets ┃ ┗  Revision by Buckets, Not Random Questions ┃ ┣  11. Practice System ┃ ┣  Easy → Medium → Hard Progression ┃ ┣  LeetCode / NeetCode / Codeforces ┃ ┣  Daily Timed Practice ┃ ┣  Weekly Mixed Contest Practice ┃ ┣  Topic-wise Sheets ┃ ┣  Re-solving Old Problems ┃ ┗  Mistake Log / Weak Area Tracker