1Trapping Rain WaterHardArrayTwo PointersDynamic Programming
Solve → 2Merge IntervalsMediumArraySorting
Solve → 3Largest Plus SignMediumArrayDynamic Programming
Solve → 4Insert Delete GetRandom O(1)MediumArrayHash TableMath
Solve → 5Word Break IIHardArrayHash TableString
Solve → 6Alien DictionaryHardArrayStringDepth-First Search
Solve → 7Time Needed to Buy TicketsEasyArrayQueueSimulation
Solve → 8Max Points on a LineHardArrayHash TableMath
Solve → 9Trapping Rain Water IIHardArrayBreadth-First SearchHeap (Priority Queue)
Solve → 10Finding the Users Active MinutesMediumArrayHash Table
Solve → 11Best Meeting PointHardArrayMathSorting
Solve → 12Number of Black BlocksMediumArrayHash TableEnumeration
Solve → 13The Skyline ProblemHardArrayDivide and ConquerBinary Indexed Tree
Solve → 14Process Tasks Using ServersMediumArrayHeap (Priority Queue)
Solve → 15Count Sub IslandsMediumArrayDepth-First SearchBreadth-First Search
Solve → 16Pascal's TriangleEasyArrayDynamic Programming
Solve → 17Minimum Elements to Add to Form a Given SumMediumArrayGreedy
Solve → 18Kth Smallest Element in a Sorted MatrixMediumArrayBinary SearchSorting
Solve → 19Flatten 2D VectorMediumArrayTwo PointersDesign
Solve → 20Minimum Cost to Connect SticksMediumArrayGreedyHeap (Priority Queue)
Solve → 21Trapping Rain WaterHardArrayTwo PointersDynamic Programming
Solve → 22Merge IntervalsMediumArraySorting
Solve → 23Pascal's TriangleEasyArrayDynamic Programming
Solve → 24Word Break IIHardArrayHash TableString
Solve → 25Time Needed to Buy TicketsEasyArrayQueueSimulation
Solve → 26Max Points on a LineHardArrayHash TableMath
Solve → 27The Skyline ProblemHardArrayDivide and ConquerBinary Indexed Tree
Solve → 28Flatten 2D VectorMediumArrayTwo PointersDesign
Solve → 29Alien DictionaryHardArrayStringDepth-First Search
Solve → 30Best Meeting PointHardArrayMathSorting
Solve → 31Kth Smallest Element in a Sorted MatrixMediumArrayBinary SearchSorting
Solve → 32Insert Delete GetRandom O(1)MediumArrayHash TableMath
Solve → 33Trapping Rain Water IIHardArrayBreadth-First SearchHeap (Priority Queue)
Solve → 34Number of Black BlocksMediumArrayHash TableEnumeration
Solve → 35Minimum Elements to Add to Form a Given SumMediumArrayGreedy
Solve → 36Finding the Users Active MinutesMediumArrayHash Table
Solve → 37Process Tasks Using ServersMediumArrayHeap (Priority Queue)
Solve → 38Count Sub IslandsMediumArrayDepth-First SearchBreadth-First Search
Solve → 39Largest Plus SignMediumArrayDynamic Programming
Solve → 40Minimum Cost to Connect SticksMediumArrayGreedyHeap (Priority Queue)
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