DSA
23 solved / 39 tracked across 3 active patterns — full 38-pattern roadmap now mapped across 8 phases (35 queued)
Two Pointers
20 of 21 problems solved across all core sub-patterns — one problem (Partition Labels) circled back for later.
Sliding Window
Not started yet — 13 problems queued, building directly on the have/need frequency logic from Hash Map.
Hash Map
Complement lookups and frequency counting solved; bidirectional mapping (Isomorphic Strings, Word Pattern) queued next.
Prefix Sum
Not started yet — 10 problems queued, the array-processing sibling to Hash Map's O(1) lookup trick.
Stack
Not started yet — 13 problems queued across four sub-patterns.
Queue and Monotonic Deque
Not started yet — 6 problems queued; this is also the on-ramp to BFS in Graph Traversal.
Linked List
Not started yet — five Easy problems queued to build comfort with pointer manipulation and traversal.
Binary Search
Not started yet — 15 problems queued; a prerequisite for the recursive tree work coming up in Trees.
Recursion and Backtracking
Not started yet — 14 problems queued; the direct prerequisite for tree recursion in Trees.
Divide and Conquer
Not started yet — 6 problems queued, closing out Searching and Recursion before Trees.
Binary Trees
Not started yet — 18 problems queued, opening Trees once Binary Search and Recursion are solid.
Binary Search Trees
Not started yet — 9 problems queued, the sorted-order specialization of Binary Trees.
Heaps and Priority Queues
Not started yet — 12 problems queued.
Tries
Not started yet — 6 problems queued. Word Search II (Recursion and Backtracking) is worth revisiting once this and backtracking are both solid.
Segment Tree and Fenwick Tree
Not started yet — 4 problems queued; lowest priority in Trees by design, since it's the least interview-common.
Graph Traversal (BFS/DFS)
Not started yet — 14 problems queued, opening Graphs once Trees feel solid, since the BFS/DFS habits transfer directly.
Topological Sort
Not started yet — 5 problems queued.
Union-Find (Disjoint Set Union)
Not started yet — 8 problems queued.
Shortest Path Algorithms
Not started yet — 7 problems queued.
Minimum Spanning Tree
Not started yet — 4 problems queued.
Advanced Graph Topics
Not started yet — 4 problems queued, closing out Graphs.
DP Foundations (1D)
Not started yet — 7 problems queued, opening the deepest phase of the roadmap.
0/1 Knapsack Pattern
Not started yet — 5 problems queued.
Unbounded Knapsack Pattern
Not started yet — 4 problems queued.
LCS and String DP (2D)
Not started yet — 9 problems queued.
Longest Increasing Subsequence Pattern
Not started yet — 5 problems queued.
Interval DP
Not started yet — 5 problems queued, one of the harder DP sub-patterns by reputation.
DP on Grids
Not started yet — 7 problems queued.
DP on Trees
Not started yet — 4 problems queued; the DP specialization of the tree-recursion habits from Trees.
State Machine DP
Not started yet — 6 problems queued, the entire buy/sell-stock family in one sub-pattern.
Bitmask DP
Not started yet — 4 problems queued, closing out DP.
Greedy Algorithms
Not started yet — 10 problems queued. Partition Labels was deferred under Two Pointers and will count toward this pattern too once it's solved.
Intervals
Not started yet — 7 problems queued.
Matrix Manipulation
Not started yet — 5 problems queued.
Bit Manipulation
Not started yet — 9 problems queued.
Math and Number Theory
Not started yet — 7 problems queued.
Design Problems
Not started yet — 7 problems queued.
Advanced String Algorithms
Not started yet — 4 problems queued, closing out the roadmap.