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Every coding-interview pattern, made visual.

10 topics, 56 patterns, and 274 hand-picked problems. Learn the tell-tale clue for each pattern, watch the solution run step by step, then practice — built by the Forward Deployed Engineers at Admitix.

Start with Arrays Browse all topics

10 topics56 patterns274 problems

Two pointers, closing in

“Once you see the motion, the code writes itself.”

The ten topics

Each topic breaks down into the handful of patterns that solve most of its problems. Pick one and watch the technique run.

015 patterns

Arrays

The patterns behind most array and subarray problems — walk pointers, slide windows, and precompute totals to turn O(n²) into O(n).

Explore24 problems

025 patterns

Strings

Two pointers, sliding windows, hashmaps, and pattern matching applied to characters and substrings.

Explore25 problems

035 patterns

Binary Search

Halve the search space every step — on sorted arrays, and on answers, ranges, and allocations.

Explore23 problems

044 patterns

Recursion

Solve a problem in terms of smaller versions of itself: divide & conquer, backtracking, and recursive search.

Explore18 problems

054 patterns

Linked List

Pointer choreography — fast/slow runners, dummy heads, recursion, and in-place reversal.

Explore20 problems

065 patterns

Stacks & Queues

LIFO and FIFO structures powering monotonic stacks, expression evaluation, and windowed queues.

Explore27 problems

076 patterns

Binary Trees & BST

Traverse, build, compare, and validate binary trees and binary search trees.

Explore28 problems

087 patterns

Priority Queues

Heaps that keep the best element one pop away — top-K, streaming medians, merges, and Dijkstra.

Explore35 problems

098 patterns

Dynamic Programming

Cache overlapping subproblems and build optimal answers from optimal sub-answers.

Explore40 problems

107 patterns

Graphs

Model things as nodes and edges, then traverse: components, shortest paths, cycles, ordering, and coloring.

Explore34 problems

You've got the patterns

Patterns get you through the screen. Shipping gets you hired.

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