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925 challenges 556 easy 323 medium 46 hard

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Matrix & 2D Arrays medium

Number of Islands

Given a 2D grid of '1' (land) and '0' (water), count the number of islands surrounded by water.

matrix graph bfs

Matrix & 2D Arrays medium

Max Area of Island

Given a 2D grid of 0s and 1s, find the maximum area of a connected group of 1s.

grid dfs connected-components

Matrix & 2D Arrays medium

Number of Islands in a Matrix

Count the number of distinct islands (connected groups of 1s) in a 2D binary matrix.

Matrix & 2D Arrays medium

Word Search Matrix

Given a 2D board and a word, determine if the word can be formed by sequentially adjacent cells (horizontally or vertically), without reusing cells.

matrix dfs strings

Matrix & 2D Arrays medium

Pacific Atlantic Matrix DFS

Given a matrix of heights, return cells that can reach both Pacific and Atlantic oceans using a DFS approach.

dfs matrix traversal

Matrix & 2D Arrays medium

Regions Cut by Slashes

Given a grid of slashes, count the number of connected regions formed by the slashes and the grid borders.

grid dfs union-find

Showing 1–6 of 6 challenges · Matrix & 2D Arrays

Matrix & 2D Arrays — Python coding challenges

What you will find here

This page lists matrix & 2d arrays challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.

Challenges vs tutorials and quizzes

Challenges test what you can build under constraints. For guided teaching, use our Python tutorials. For quick checks, try quizzes or copy snippets from code samples.