Amazon
2015 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| 1. Two Sum | Easy | 100% | TopicsArrayHash Table |
| 42. Trapping Rain Water | Hard | 87.9% | TopicsArrayTwo PointersDynamic ProgrammingStackMonotonic Stack |
| 146. LRU Cache | Medium | 87.9% | TopicsHash TableLinked ListDesignDoubly-Linked List |
| 200. Number of Islands | Medium | 85% | TopicsArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix |
| 3. Longest Substring Without Repeating Characters | Medium | 83.9% | TopicsHash TableStringSliding Window |
| 121. Best Time to Buy and Sell Stock | Easy | 83.8% | TopicsArrayDynamic Programming |
| 49. Group Anagrams | Medium | 80.1% | TopicsArrayHash TableStringSorting |
| 2. Add Two Numbers | Medium | 79.7% | TopicsLinked ListMathRecursion |
| 5. Longest Palindromic Substring | Medium | 78.6% | TopicsTwo PointersStringDynamic ProgrammingManacher |
| 3Sum | Medium | 78.6% | TopicsArrayTwo PointersSorting |
| 767. Reorganize String | Medium | 78% | TopicsHash TableStringGreedySortingHeap (Priority Queue)Counting |
| 4. Median of Two Sorted Arrays | Hard | 76.8% | TopicsArrayBinary SearchDivide and Conquer |
| 56. Merge Intervals | Medium | 76.4% | TopicsArraySortingQuicksort |
| 11. Container With Most Water | Medium | 76.2% | TopicsArrayTwo PointersGreedy |
| 875. Koko Eating Bananas | Medium | 74.9% | TopicsArrayBinary Search |
| 207. Course Schedule | Medium | 74.5% | TopicsDepth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph |
| 20. Valid Parentheses | Easy | 74.3% | TopicsStringStackBracket Sequences |
| 560. Subarray Sum Equals K | Medium | 74% | TopicsArrayHash TablePrefix Sum |
| 14. Longest Common Prefix | Easy | 73.8% | TopicsArrayStringTrie |
| 23. Merge k Sorted Lists | Hard | 73.5% | TopicsLinked ListDivide and ConquerHeap (Priority Queue)Merge SortTournament Sort |
| 994. Rotting Oranges | Medium | 73.3% | TopicsArrayBreadth-First SearchMatrix |
| 33. Search in Rotated Sorted Array | Medium | 72% | TopicsArrayBinary Search |
| 53. Maximum Subarray | Medium | 72% | TopicsArrayDivide and ConquerDynamic Programming |
| 347. Top K Frequent Elements | Medium | 71.5% | TopicsArrayHash TableDivide and ConquerSortingHeap (Priority Queue)Bucket SortCountingQuickselect |
| Longest Consecutive Sequence | Medium | 70.9% | TopicsArrayHash TableUnion-Find |
