ALL TRACKS
Every pattern family, yours to explore in any order. The guided path is the fastest route — but the wheel is always yours.
Master fundamental array manipulation and hash map patterns. These problems form the foundation for more advanced algorithms.
Learn to traverse and manipulate binary trees and BSTs. Master recursion, DFS, and tree construction.
Explore graph traversal algorithms. Learn DFS, BFS, and how to navigate node-edge relationships.
Master the two-pointer technique for array and string problems. Eliminate nested loops with smart pointer placement.
Learn to maintain a dynamic window over sequences. Essential for substring, subarray, and contiguous-range problems.
Use stacks to solve bracket matching, expression evaluation, and monotonic problems with O(n) elegance.
Harness O(log n) search for sorted arrays, rotated arrays, and even answer-space problems.
Traverse, reverse, and manipulate singly linked lists. Master fast/slow pointer patterns.
Expand binary tree skills: inversion, depth, structural comparison, and subtree matching.
Track top-K elements, schedule with priorities, and stream medians using min/max heaps.
Break problems into overlapping subproblems. Memoize, tabulate, and optimize state transitions.
Explore all valid configurations with depth-first search, smart pruning, and undo on retreat.
Sort, merge, and reason about overlapping ranges. Patterns reused across scheduling and timeline problems.
Make locally optimal choices that lead to globally optimal solutions. Single-pass elegance.
Advanced linked list patterns: cycle detection, k-way merging, deep cloning, and arithmetic on lists.
Tree traversal patterns: BFS level order, BST navigation, tree construction, and side views.
Topological sort, DFS from boundaries, union-find, and tree validation. Apply graph algorithms to real problems.
Prefix tree for efficient string lookup, autocomplete, and word search. Powerful for dictionary problems.
XOR tricks, bit counting, and arithmetic shortcuts. Master O(1) operations on binary representations.