| Median of Two Sorted Arrays | HARD | | ArrayBinary SearchDivide and Conquer | |
| Letter Combinations of a Phone Number | MEDIUM | | Hash TableStringBacktracking | |
| Trapping Rain Water | HARD | | ArrayTwo PointersDynamic ProgrammingStackMonotonic Stack | |
| Maximum Points After Collecting Coins From All Nodes | HARD | | ArrayDynamic ProgrammingBit ManipulationTreeDepth-First SearchMemoization | |
| Best Time to Buy and Sell Stock | EASY | | ArrayDynamic Programming | |
| Longest Consecutive Sequence | MEDIUM | | ArrayHash TableUnion-Find | |
| Maximum Product Subarray | MEDIUM | | ArrayDynamic Programming | |
| Relative Sort Array | EASY | | ArrayHash TableSortingCounting Sort | |
| House Robber | MEDIUM | | ArrayDynamic Programming | |
| Basic Calculator II | MEDIUM | | MathStringStack | |
| Sliding Window Maximum | HARD | | ArrayQueueSliding WindowHeap (Priority Queue)Monotonic Queue | |
| Maximum Strength of K Disjoint Subarrays | HARD | | ArrayDynamic ProgrammingPrefix Sum | |
| Removing Minimum Number of Magic Beans | MEDIUM | | ArrayGreedySortingEnumerationPrefix Sum | |
| Find the Sum of the Power of All Subsequences | HARD | | ArrayDynamic Programming | |
| Minimum Cost Walk in Weighted Graph | HARD | | ArrayBit ManipulationUnion-FindGraph Theory | |
| Minimum Deletions to Make String K-Special | MEDIUM | | Hash TableStringGreedySortingCounting | |
| Greatest Sum Divisible by Three | MEDIUM | | ArrayDynamic ProgrammingGreedySorting | |
| Query Kth Smallest Trimmed Number | MEDIUM | | ArrayStringDivide and ConquerSortingHeap (Priority Queue)Radix SortQuickselect | |
| Insert Delete GetRandom O(1) | MEDIUM | | ArrayHash TableMathDesignRandomized | |
| Equal Row and Column Pairs | MEDIUM | | ArrayHash TableMatrixSimulation | |