Minimum Path Sum Matrix
Implement a function that computes the minimum path sum from the top-left to the bottom-right of a grid moving only right or down.
Dungeon Game Minimum Health
Compute the minimum initial health needed to reach the bottom-right corner of a dungeon grid without health dropping to zero or below.
Floyd-Warshall: All-Pairs Shortest Paths
Implement the Floyd-Warshall algorithm to find all-pairs shortest path distances in a directed graph with possibly negative weights but no negative cycles.
Count square submatrices with all ones
Count all square submatrices consisting entirely of 1s in a binary matrix.
Largest Plus Sign
Compute the largest possible plus sign of 1s in an n x n grid with some cells set to 0.
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Guide: free Python coding challenges
Practice Python by solving problems
PythonSkillset challenges are hands-on coding exercises from beginner to advanced. Open a challenge, read the problem, write Python in the split-pane editor, and run tests with Pyodide — no install required.
How to use the arena
- Pick a category — basics, algorithms, strings, and more
- Open a challenge, read the statement, and edit the starter code
- Run tests, fix failures, then try a related quiz or tutorial lesson
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.