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Master these coding challenges to ace your next technical interview. Handpicked problems with personalized spaced repetition.

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Showing 76-100 of 104 matching problems.

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Title	Difficulty	Topics
170. Two Sum III - Data structure design Open sourcePremium	Easy	ArrayHash TableTwo Pointers+2 more
174. Dungeon Game Open source	Hard	ArrayDynamic ProgrammingMatrix
179. Largest Number Open source	Medium	ArrayStringGreedy+1 more
188. Best Time to Buy and Sell Stock IV Open source	Hard	ArrayDynamic Programming
189. Rotate Array Open source	Medium	ArrayMathTwo Pointers
198. House Robber Open source	Medium	ArrayDynamic Programming
200. Number of Islands Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 more
204. Count Primes Open source	Medium	ArrayMathEnumeration+4 more
209. Minimum Size Subarray Sum Open source	Medium	ArrayBinary SearchSliding Window+1 more
212. Word Search II Open source	Hard	ArrayStringBacktracking+2 more
213. House Robber II Open source	Medium	ArrayDynamic Programming
215. Kth Largest Element in an Array Open source	Medium	ArrayDivide and ConquerSorting+2 more
216. Combination Sum III Open source	Medium	ArrayBacktracking
217. Contains Duplicate Open source	Easy	ArrayHash TableSorting
218. The Skyline Problem Open source	Hard	ArrayDivide and ConquerBinary Indexed Tree+5 more
219. Contains Duplicate II Open source	Easy	ArrayHash TableSliding Window
220. Contains Duplicate III Open source	Hard	ArraySliding WindowSorting+2 more
221. Maximal Square Open source	Medium	ArrayDynamic ProgrammingMatrix
228. Summary Ranges Open source	Easy	Array
229. Majority Element II Open source	Medium	ArrayHash TableSorting+2 more
238. Product of Array Except Self Open source	Medium	ArrayPrefix Sum
239. Sliding Window Maximum Open source	Hard	ArrayQueueSliding Window+3 more
240. Search a 2D Matrix II Open source	Medium	ArrayBinary SearchDivide and Conquer+1 more
243. Shortest Word Distance Open sourcePremium	Easy	ArrayString
244. Shortest Word Distance II Open sourcePremium	Medium	ArrayHash TableTwo Pointers+2 more