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Python Coding Challenges

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925 challenges 556 easy 323 medium 46 hard
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Two Pointers & Sliding Window medium

Count Nice Subarrays

Given an array of integers, count the number of contiguous subarrays that contain exactly k odd numbers.

sliding-window two-pointers subarray
+25 pts 25m
Two Pointers & Sliding Window medium

Three Sum

Given an array of integers, return all unique triplets that sum to zero.

sorting two-pointer unique-triplets
+25 pts 25m
Two Pointers & Sliding Window medium

Closest Three Sum

Given an array of integers and a target, return the sum of three numbers that is closest to the target.

sorting two-pointers array
+20 pts 20m
Two Pointers & Sliding Window medium

Minimum Size Subarray Sum

Given an array of positive integers, return the minimal length of a contiguous subarray with sum at least target, or 0 if none exists.

sliding-window two-pointers array
+25 pts 30m
Two Pointers & Sliding Window medium

Fruit into Baskets

Given an array of integers representing fruit types, return the maximum number of fruits you can collect in a contiguous subarray with at most two distinct types.

sliding-window two-pointers hash-map
+25 pts 25m
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
+25 pts 25m
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
+25 pts 25m

Showing 1–7 of 7 challenges · medium · 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.