Amazon
2015 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| 2316. Count Unreachable Pairs of Nodes in an Undirected Graph | Medium | 27.9% | TopicsDepth-First SearchBreadth-First SearchUnion-FindGraph Theory |
| 2333. Minimum Sum of Squared Difference | Medium | 27.9% | TopicsArrayBinary SearchGreedySortingHeap (Priority Queue) |
| 2396. Strictly Palindromic Number | Medium | 27.9% | TopicsMathTwo PointersBrainteaser |
| 2502. Design Memory Allocator | Medium | 27.9% | TopicsArrayHash TableDesignSimulation |
| 2583. Kth Largest Sum in a Binary Tree | Medium | 27.9% | TopicsTreeBreadth-First SearchSortingBinary Tree |
| 2747. Count Zero Request Servers | Medium | 27.9% | TopicsArrayHash TableSliding WindowSorting |
| 2801. Count Stepping Numbers in Range | Hard | 27.9% | TopicsStringDynamic Programming |
| 2938. Separate Black and White Balls | Medium | 27.9% | TopicsTwo PointersStringGreedy |
| 3531. Count Covered Buildings | Medium | 27.9% | TopicsArrayHash TableSorting |
| 3010. Divide an Array Into Subarrays With Minimum Cost I | Easy | 27.9% | TopicsArraySortingEnumeration |
| N-Queens II | Hard | 26.6% | TopicsBacktrackingAlgorithm X |
| 93. Restore IP Addresses | Medium | 26.6% | TopicsStringBacktracking |
| 129. Sum Root to Leaf Numbers | Medium | 26.6% | TopicsTreeDepth-First SearchBinary Tree |
| Excel Sheet Column Number | Easy | 26.6% | TopicsMathString |
| Delete Duplicate Emails | Easy | 26.6% | TopicsDatabase |
| H-Index | Medium | 26.6% | TopicsArraySortingCounting Sort |
| Find the Celebrity | Medium | 26.6% | TopicsTwo PointersGraph TheoryInteractive |
| 286. Walls and Gates | Medium | 26.6% | TopicsArrayBreadth-First SearchMatrix |
| Game of Life | Medium | 26.6% | TopicsArrayMatrixSimulation |
| Count of Smaller Numbers After Self | Hard | 26.6% | TopicsArrayBinary SearchDivide and ConquerBinary Indexed TreeSegment TreeMerge SortOrdered SetTreap |
| 329. Longest Increasing Path in a Matrix | Hard | 26.6% | TopicsArrayDynamic ProgrammingDepth-First SearchBreadth-First SearchGraph TheoryTopological SortMemoizationMatrixDirected Acyclic Graph |
| Design Hit Counter | Medium | 26.6% | TopicsArrayBinary SearchDesignQueueData Stream |
| Battleships in a Board | Medium | 26.6% | TopicsArrayDepth-First SearchMatrix |
| All O`one Data Structure | Hard | 26.6% | TopicsHash TableLinked ListDesignDoubly-Linked List |
| 508. Most Frequent Subtree Sum | Medium | 26.6% | TopicsHash TableTreeDepth-First SearchBinary TreeDP on Trees |
