N-Queens Solutions
Implement a function to count the number of distinct ways to place n queens on an n×n board.
Knight Tour Count
Implement a backtracking search to count all ways a knight can visit every cell on a 5x5 board exactly once starting from (0,0).
Tiling dominoes count
Given a 2 x n board, count the distinct tilings using 2 x 1 dominoes.
N-Queens Count
Count the number of distinct valid placements of n non-attacking queens on an n×n chessboard.
Word Search Backtrack
Determine if a given word exists in a 2D board by tracing adjacent cells without reusing any cell.
Painter Partition Problem
Given board lengths and k painters, find the minimum possible maximum total length a painter must paint.
Valid Sudoku Board
Determine if a 9x9 Sudoku board is valid by checking rows, columns, and 3x3 sub-boxes.
Valid Sudoku Validator
Determine if a given 9x9 Sudoku board is valid by checking rows, columns, and 3x3 boxes.
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.
Showing 1–9 of 9 challenges
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.