Apple
282 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| 146. LRU Cache | Medium | 100% | TopicsHash TableLinked ListDesignDoubly-Linked List |
| 1. Two Sum | Easy | 85.8% | TopicsArrayHash Table |
| 56. Merge Intervals | Medium | 84.1% | TopicsArraySortingQuicksort |
| Design Hit Counter | Medium | 80.4% | TopicsArrayBinary SearchDesignQueueData Stream |
| 121. Best Time to Buy and Sell Stock | Easy | 79.9% | TopicsArrayDynamic Programming |
| 200. Number of Islands | Medium | 79.9% | TopicsArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix |
| Rotate Array | Medium | 77.7% | TopicsArrayMathTwo Pointers |
| 206. Reverse Linked List | Easy | 77.1% | TopicsLinked ListRecursion |
| 347. Top K Frequent Elements | Medium | 77.1% | TopicsArrayHash TableDivide and ConquerSortingHeap (Priority Queue)Bucket SortCountingQuickselect |
| 14. Longest Common Prefix | Easy | 75.8% | TopicsArrayStringTrie |
| 36. Valid Sudoku | Medium | 74.5% | TopicsArrayHash TableMatrix |
| 49. Group Anagrams | Medium | 73.8% | TopicsArrayHash TableStringSorting |
| 210. Course Schedule II | Medium | 73.8% | TopicsDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort |
| 207. Course Schedule | Medium | 71.6% | TopicsDepth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph |
| 20. Valid Parentheses | Easy | 69.9% | TopicsStringStackBracket Sequences |
| 125. Valid Palindrome | Easy | 69.9% | TopicsTwo PointersString |
| 3. Longest Substring Without Repeating Characters | Medium | 69% | TopicsHash TableStringSliding Window |
| 54. Spiral Matrix | Medium | 68.1% | TopicsArrayMatrixSimulation |
| 215. Kth Largest Element in an Array | Medium | 68.1% | TopicsArrayDivide and ConquerSortingHeap (Priority Queue)Quickselect |
| 713. Subarray Product Less Than K | Medium | 68.1% | TopicsArrayBinary SearchSliding WindowPrefix Sum |
| 981. Time Based Key-Value Store | Medium | 68.1% | TopicsHash TableStringBinary SearchDesign |
| Best Time to Buy and Sell Stock II | Medium | 67.1% | TopicsArrayDynamic ProgrammingGreedy |
| 238. Product of Array Except Self | Medium | 67.1% | TopicsArrayPrefix Sum |
| 857. Minimum Cost to Hire K Workers | Hard | 66.1% | TopicsArrayGreedySortingHeap (Priority Queue) |
| 23. Merge k Sorted Lists | Hard | 65% | TopicsLinked ListDivide and ConquerHeap (Priority Queue)Merge SortTournament Sort |
