Citadel
75 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| Sliding Window Maximum | Hard | 100% | TopicsArrayQueueSliding WindowHeap (Priority Queue)Monotonic QueueRange Minimum/Maximum Query |
| 2484. Count Palindromic Subsequences | Hard | 100% | TopicsStringDynamic Programming |
| 1801. Number of Orders in the Backlog | Medium | 98.5% | TopicsArrayHeap (Priority Queue)Simulation |
| 647. Palindromic Substrings | Medium | 95.1% | TopicsTwo PointersStringDynamic Programming |
| 121. Best Time to Buy and Sell Stock | Easy | 89.1% | TopicsArrayDynamic Programming |
| 295. Find Median from Data Stream | Hard | 89.1% | TopicsTwo PointersDesignSortingHeap (Priority Queue)Data Stream |
| 1515. Best Position for a Service Centre | Hard | 89.1% | TopicsArrayMathGeometryRandomized |
| 56. Merge Intervals | Medium | 89.1% | TopicsArraySortingQuicksort |
| Insert Delete GetRandom O(1) | Medium | 86.7% | TopicsArrayHash TableMathDesignRandomized |
| Minimum Costs Using the Train Line | Hard | 84.1% | TopicsArrayDynamic Programming |
| 981. Time Based Key-Value Store | Medium | 84.1% | TopicsHash TableStringBinary SearchDesign |
| 3186. Maximum Total Damage With Spell Casting | Medium | 81.2% | TopicsArrayHash TableTwo PointersBinary SearchDynamic ProgrammingSortingCounting |
| Evaluate Division | Medium | 81.2% | TopicsArrayStringDepth-First SearchBreadth-First SearchUnion-FindGraph TheoryShortest PathBellman–Ford AlgorithmFloyd–Warshall Algorithm |
| 2661. First Completely Painted Row or Column | Medium | 81.2% | TopicsArrayHash TableMatrix |
| 718. Maximum Length of Repeated Subarray | Medium | 81.2% | TopicsArrayBinary SearchDynamic ProgrammingSliding WindowRolling HashHash Function |
| Best Time to Buy and Sell Stock with Cooldown II | Medium | 81.2% | TopicsArrayDynamic Programming |
| Evaluate Reverse Polish Notation | Medium | 77.8% | TopicsArrayMathStack |
| 146. LRU Cache | Medium | 74% | TopicsHash TableLinked ListDesignDoubly-Linked List |
| LFU Cache | Hard | 74% | TopicsHash TableLinked ListDesignDoubly-Linked List |
| 2050. Parallel Courses III | Hard | 74% | TopicsArrayDynamic ProgrammingGraph TheoryTopological SortDirected Acyclic Graph |
| 3484. Design Spreadsheet | Medium | 74% | TopicsArrayHash TableStringDesignMatrix |
| 210. Course Schedule II | Medium | 69.4% | TopicsDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort |
| 759. Employee Free Time | Hard | 69.4% | TopicsArraySweep LineSortingHeap (Priority Queue) |
| 1229. Meeting Scheduler | Medium | 69.4% | TopicsArrayTwo PointersSorting |
| 1606. Find Servers That Handled Most Number of Requests | Hard | 69.4% | TopicsArrayHeap (Priority Queue)SimulationOrdered Set |
