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925 challenges 556 easy 323 medium 46 hard

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Two Pointers & Sliding Window easy

Container With Most Water

Compute the maximum area between two vertical lines in an array of heights.

two-pointers array area-calculation

Two Pointers & Sliding Window medium

Trapping Rain Water (Two Pointers)

Given an array of non-negative integers representing elevation heights, compute how much water can be trapped after rain.

two-pointers arrays water-trapping

Two Pointers & Sliding Window medium

Sliding Window Median

Given a list of integers and a positive window size k, return the median of each sliding window of length k.

sliding-window median sorting

Two Pointers & Sliding Window medium

Four Sum

Find all unique quadruplets in an array that sum to a given target.

two-pointers sorting set

Two Pointers & Sliding Window medium

Longest Repeating Character Replacement

Given a string and an integer k, return the length of the longest substring that can be made of identical characters after at most k replacements.

sliding-window strings hash-map

Two Pointers & Sliding Window medium

Count Nice Subarrays

Count subarrays that contain exactly k odd numbers.

sliding-window two-pointers counting

Showing 25–30 of 30 challenges · Two Pointers & Sliding Window

Two Pointers & Sliding Window — Python coding challenges

What you will find here

This page lists two pointers & sliding window 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.