Valid parentheses
Return True if brackets in the string close in the correct order.
Binary search
Return the index of target in a sorted list, or -1 if not present.
Index of peak element
Implement a function that returns the index of any peak element in a given integer array.
Count pairs with given difference
Count how many unordered pairs in a list have a given absolute difference using an efficient approach.
Previous Smaller Element
Find the nearest previous index with a smaller value for every element in an array.
Pascal Triangle Row
Given a non-negative integer n, return the nth row of Pascal's triangle as a list of integers.
Employee Hierarchy
Build an employee hierarchy tree and compute the total number of direct and indirect reports for each employee.
Union Find Class
Implement a UnionFind class with find and union operations supporting path compression and union by size.
Bubble Sort
Implement bubble sort that sorts a list of numbers in ascending order.
Selection Sort Implementation
Implement selection sort to sort a list of numbers in ascending order.
Shell Sort
Implement Shell sort, an in-place comparison sort that generalizes insertion sort, using a gap sequence that shrinks by half each pass.
Exponential Search
Implement exponential search to find any valid index of a target in a sorted list.
Showing 12 challenges · easy · Data Structures & Algorithms
Data Structures & Algorithms — Python coding challenges
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This page lists data structures & algorithms 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.
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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.