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Python Coding
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925 challenges 556 easy 323 medium 46 hard

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Recursion & Backtracking medium

Combination Generator

Write a recursive function that returns all combinations of length k from a list of distinct integers.

recursion backtracking combinations

Recursion & Backtracking medium

Generate Parentheses

Given n, generate all valid strings of n pairs of parentheses.

backtracking recursion parentheses

Recursion & Backtracking medium

Letter Combinations of a Phone Number

Given a string of digits, return all possible letter combinations that the number could represent on a phone keypad.

recursion backtracking string

Recursion & Backtracking medium

Combination Sum

Given a list of distinct positive integers and a target, return all unique combinations that sum to the target.

backtracking recursion combinations

Showing 1–4 of 4 challenges · medium · Recursion & Backtracking

Recursion & Backtracking — Python coding challenges

What you will find here

This page lists recursion & backtracking 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.