DSA Interview Pattern Mastery4-Day Streak Active
Mastering these 25 patterns covers 90%+ of technical rounds at Amazon, Qualcomm, and Microsoft.
Practice Score
625 XP
Roadmap Progress
20%
5 of 25 questions mastered20 patterns remaining
Phase 1: Foundations, Arrays & Two Pointers
Master Time/Space Big-O, Hash Maps, Two-Pointer technique, and Sliding Window ranges.
Two SumEasy✓ +25 XP
Pattern: HashMap / ArrayValid AnagramEasy✓ +25 XP
Pattern: Hash Table / CountingValid PalindromeEasy✓ +25 XP
Pattern: Two PointersBest Time to Buy and Sell StockEasy✓ +25 XP
Pattern: Sliding WindowLongest Substring Without Repeating CharactersMedium+25 XP
Pattern: Sliding WindowContainer With Most WaterMedium+25 XP
Pattern: Two Pointers3SumMedium+25 XP
Pattern: Two PointersPhase 2: Linear Data Structures & Binary Search
Pointer reversal, cycle detection, monotonic stacks for nearest elements, and logarithmic binary search.
Valid ParenthesesEasy✓ +25 XP
Pattern: StackReverse Linked ListEasy+25 XP
Pattern: Linked List Pointer ManipulationMerge Two Sorted ListsEasy+25 XP
Pattern: Linked ListBinary SearchEasy+25 XP
Pattern: Binary SearchSearch in Rotated Sorted ArrayMedium+25 XP
Pattern: Modified Binary SearchDaily TemperaturesMedium+25 XP
Pattern: Monotonic StackPhase 3: Trees, Graphs & Priority Queues
Hierarchical trees, BFS level-order, DFS recursion, and graph grid traversal (Islands).
Invert Binary TreeEasy+25 XP
Pattern: Tree DFS TraversalMaximum Depth of Binary TreeEasy+25 XP
Pattern: Tree DFS / BFSValidate Binary Search TreeMedium+25 XP
Pattern: BST PropertiesLowest Common Ancestor of a BSTMedium+25 XP
Pattern: BST SearchNumber of IslandsMedium+25 XP
Pattern: Graph BFS / DFS Matrix TraversalClone GraphMedium+25 XP
Pattern: Graph Traversal / HashMapKth Largest Element in an ArrayMedium+25 XP
Pattern: Min-Heap / Priority QueuePhase 4: Dynamic Programming & Backtracking
Overlapping subproblems, state transitions, memoization, 0/1 knapsack, and decision trees.