Python coding challenges: "stack"

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All Python Basics Strings & Text Lists & Arrays Dicts & Sets Functions & Closures OOP & Classes Data Structures & Algorithms Advanced Python Iterators & Generators Decorators & Context Managers Error Handling & Exceptions Regular Expressions Math & Number Theory Bit Manipulation Dynamic Programming Trees & Binary Trees Graphs & Graph Algorithms Recursion & Backtracking Greedy Algorithms Binary Search Two Pointers & Sliding Window Stacks & Queues Heaps & Priority Queues Linked Lists Matrix & 2D Arrays Datetime & Time Calculations Data Formats & Parsing SQL & SQLite Numpy & Vectorized Computing Cryptography & Hashing

Strings & Text hard

Basic Calculator III

Implement a recursive descent parser to evaluate a fully parenthesized arithmetic expression with +, -, *, / and parentheses.

parsing string expression

+45 pts 40m

Data Structures & Algorithms hard

Largest Rectangle in Histogram

Given an array of bar heights, compute the largest rectangle that can be formed by consecutive bars.

histogram stack maximum-area

+40 pts 35m

Data Structures & Algorithms hard

Largest Area Histogram Matrix

Given a binary matrix, compute the largest rectangle area consisting entirely of 1s.

stack histogram matrix

+40 pts 35m

Greedy Algorithms hard

Remove K Digits to Form the Smallest Number

Given a non-negative integer as a string, remove exactly k digits to form the smallest possible integer without leading zeros.

greedy stack string

+45 pts 35m

Showing 1–4 of 4 challenges · hard

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.

Python Coding Challenges