Pattern Map

Every topic here leads to the next one up. Start at the bottom, work upward, and the harder topics stop feeling hard because you already know what they're built on.

Click a topic to open its lesson. Hover over one to trace what it builds on and what it unlocks.

Pattern

Backtracking

Try a choice, undo it, try the next

Pattern

Dynamic Programming

Cache subproblems, solve them once

Data structure

Tree

Nodes with parent and child links

Pattern

Tree BFS

Walk a tree level by level

Data structure

Graph

Nodes and edges, adjacency first

Pattern

Graph DFS

Follow one path to the end

Pattern

Graph BFS

Explore outward, fewest hops first

Pattern

Sliding Window

A moving slice of the list

Pattern

Intervals

Sort ranges, then merge overlaps

Pattern

Modified Binary Search

Halve a sorted range each step

Data structure

Queue / Stack

Add and remove from the ends

Data structure

Heap

The smallest item, always on top

Pattern

Linked List Manipulation

Rewire next pointers in place

Data structure

List

Ordered values you index and scan

Data structure

Set

Fast membership checks, no duplicates

Data structure

Dictionary

Look things up by key

Pattern

Two Pointers

Two indices walk the list together

InterviewCrunch

Pattern Map