DSA & Algorithms

DSA & Algorithms

Interview pattern map — arrays to DP/backtracking — with Big-O, templates, and LeetCode drills.

• DSA Advanced & Company Favorites

  16 studies
  1. 1.DSA Advanced & Company Favorites - Tries, Greedy, Strings, Design & MoreAdvanced company-favorite DSA patterns beyond the fundamentals track: tries, bits, greedy, strings, DP advanced, design, concurrency, and mock drills.
  2. 2.Tries / Prefix TreesPrefix trees for autocomplete, Word Search II, and dictionary prefix queries with O(L) ops.
  3. 3.Bit Manipulation & BitmasksBit tricks, XOR family, subset bitmasks, and when FAANG asks bit puzzles.
  4. 4.Greedy Algorithms - Proof Sketches & Exchange ArgumentsWhen greedy works: exchange arguments, stay-ahead proofs, and classic interview greeds.
  5. 5.Intervals Advanced - Meeting Rooms, Merge, Sweep PrioritiesMeeting rooms, merge intervals, employee free time, and sweep-line priority queues.
  6. 6.Strings - Parsing, Rolling Hash & KMP intuitionString parsing patterns, Rabin-Karp rolling hash, and KMP LPS intuition for interviews.
  7. 7.Math & Number Theory for Interviews (gcd, mod, primes, combinatorics basics)gcd/lcm, modular arithmetic, primes/sieve, and combinatorics basics asked in coding rounds.
  8. 8.Matrix Traversal - Spiral, Islands, DFS/BFS on gridsSpiral order, rotate, islands variants, and grid BFS/DFS depth beyond basic flood fill.
  9. 9.Recursion & Divide-and-Conquer - Master theorem intuition, merge patternsDivide-and-conquer templates, merge patterns, Master theorem intuition for interview analysis.
  10. 10.DP Advanced - State machine DP, Digit DP intro, Interval DP, Bitmask DPState-machine DP, digit DP intro, interval DP, and bitmask DP for harder company rounds.
  11. 11.Graphs Advanced - SCC, Bridges, Articulation, BipartiteTarjan/Kosaraju SCC, bridges, articulation points, and bipartite coloring for advanced graph rounds.
  12. 12.Trees Advanced - LCA, Rerooting, Path aggregatesLCA binary lifting intuition, rerooting DP, and path aggregates on trees.
  13. 13.Design Data Structures - LRU/LFU, MinStack, Snapshot, RandomizedSetDesign coding favorites: LRU/LFU, MinStack, Snapshot Array, RandomizedSet with O(1) targets.
  14. 14.Concurrency Interview Basics - locks, barriers, bounded bufferLeetCode concurrency patterns: locks, barriers, bounded buffer, print-in-order style problems.
  15. 15.Coding-round System Design Lite - rate limiter, URL shortener coding shapesCoding-round shaped designs: rate limiter, URL shortener, tiny LFU/cache - not full HLD.
  16. 16.Mock Interview Drills - timed sets by company theme + checklistTimed mock sets by company theme (Meta/Amazon/Google-style) plus checklist and wave-1+2 coverage map.

• DSA Interview Patterns

  21 studies
  1. 1.DSA for Interviews — Pattern Map, Complexity & How to DrillInterview DSA pattern map, Big-O cheat sheet, how to pick a pattern, and drill pacing for 20 core patterns.
  2. 2.Arrays & Two Pointers — Opposite Ends, Same Direction & PartitionOpposite-end and same-direction two pointers for sorted arrays, partitions, and O(n) pair scans.
  3. 3.Sliding Window — Fixed & Variable Windows for SubarraysFixed and variable sliding windows for subarray/substring constraints in O(n).
  4. 4.Prefix Sums & Difference Arrays — Range Queries in O(1)Prefix sums and difference arrays for range sums and range updates.
  5. 5.Binary Search & Search-on-Answer — Predicates, Bounds & FeasibilityClassic binary search plus search-on-answer over monotonic feasibility predicates.
  6. 6.Sorting, Intervals & Sweep Line — Merge, Overlap & EventsSort plus sweep for merge intervals, overlaps, and event-based line sweeps.
  7. 7.Stack & Monotonic Stack — Next Greater, Histograms & ParsingMonotonic stacks for next-greater/smaller, histogram areas, and expression parsing.
  8. 8.Queue, Deque & Monotonic Queue — Sliding Extrema & BFS HelpersDeque and monotonic queue for sliding-window maxima and BFS-friendly fronts.
  9. 9.Linked Lists — Reverse, Merge, Cycle Detection & Dummy HeadsIn-place reverse, merge, Floyd cycle, and dummy-head patterns for list surgery.
  10. 10.Binary Trees — DFS (Preorder, Inorder, Postorder; Recursion & Stack)Tree DFS orders with recursion and explicit stack; path and subtree aggregates.
  11. 11.Binary Trees — BFS / Level Order — Layers, Width & ZigzagLevel-order BFS for layers, width, zigzag, and closest-value-by-depth.
  12. 12.Binary Search Trees — Inorder, Bounds, LCA & ValidateBST invariants: inorder sortedness, insert/delete sketch, validate, and LCA.
  13. 13.Heaps, Priority Queues & Top-K — n-largest, Merge K & StreamingMin/max heaps for top-K, merge K lists, and streaming extremes.
  14. 14.Hashing, Frequency Maps & Counting — Two Sum Family & AnagramsHash maps for complements, frequency, anagrams, and O(1) expected lookups.
  15. 15.Graphs — DFS & BFS Traversal — Components, Cycles & Grid FloodGraph DFS/BFS for components, cycles, bipartite checks, and grid flood fill.
  16. 16.Graphs — Topological Sort & DAGs — Kahn, DFS Finish Times & CyclesKahn and DFS topo sort on DAGs; detect cycles and order dependencies.
  17. 17.Union-Find (Disjoint Set Union) — Connectivity, Components & KruskalDSU with path compression and union-by-rank for dynamic connectivity.
  18. 18.Shortest Paths — Dijkstra, Bellman-Ford & When Not To Use ThemDijkstra vs Bellman-Ford vs BFS-on-unweighted; negative edges and when not to.
  19. 19.Dynamic Programming — 1D Patterns — Climb, House Robber, LIS Families1D DP templates: recurrence, rolling arrays, and classic climb/robber/LIS shapes.
  20. 20.Dynamic Programming — 2D, Knapsack & Grids — Paths, Subsets & LCS2D DP for grids, 0/1 knapsack, LCS/edit distance, and space-optimized rolls.
  21. 21.Backtracking & Search Trees — Subsets, Permutations, Combinations & PruningBacktracking templates with choose/explore/unchoose and pruning for interviews.