psychology

Data Structures & Algorithms

Patterns, complexity, and trade-offs properly indexed.

11patterns

Mastery = recognizing patterns.

Core Operations Arrays & Prefix Techniques Two Pointers Sliding Window Hashing & Frequency Maps Binary Search Recursion & Backtracking Trees Graphs Heaps & Priority Queues Dynamic Programming

Core DSA Patterns

#001

FoundationMechanics

Core Operations

The mechanical foundation beneath every pattern. Mastery of operational precision.

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#002

ArrayPrefix Sum

Arrays & Prefix Techniques

Precompute information to answer queries efficiently

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#003

ArrayString

Two Pointers

Reduce nested loops by maintaining controlled window boundaries

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#004

ArrayString

Sliding Window

Track dynamic subarrays or substrings efficiently

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#005

HashMapSet

Hashing & Frequency Maps

Trade space for time using constant-time lookups

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#006

SearchLogN

Binary Search

Apply monotonic logic beyond sorted arrays

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#007

RecursionDFS

Recursion & Backtracking

Explore state spaces with controlled branching

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#008

TreeDFSBFS

Trees

Hierarchical data and traversal strategies

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#009

GraphDFSBFS

Graphs

Model relationships and dependencies

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#010

Heap

Heaps & Priority Queues

Efficiently track min/max elements

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#011

Dynamic Programming

Optimize overlapping subproblems with state transitions

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Pattern Philosophy

✓Patterns are reusable thinking tools
✓Most problems combine multiple patterns
✓Focus on invariants and constraints
✓Always analyze time and space trade-offs

Algorithms are about constraints, not cleverness.

What Comes Next?

drawPattern deep dives

drawProblem breakdowns with trade-offs

drawMachine coding integration

drawDesign thinking overlays