Amazon
2015 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| Number of Provinces | Medium | 50.1% | TopicsDepth-First SearchBreadth-First SearchUnion-FindGraph Theory |
| Fibonacci Number | Easy | 50.1% | TopicsMathDynamic ProgrammingRecursionMemoization |
| 1752. Check if Array Is Sorted and Rotated | Easy | 50.1% | TopicsArray |
| 110. Balanced Binary Tree | Easy | 49.7% | TopicsTreeDepth-First SearchBinary Tree |
| Largest Number | Medium | 49.7% | TopicsArrayStringGreedySorting |
| Evaluate Division | Medium | 49.7% | TopicsArrayStringDepth-First SearchBreadth-First SearchUnion-FindGraph TheoryShortest PathBellman–Ford AlgorithmFloyd–Warshall Algorithm |
| 66. Plus One | Easy | 49.4% | TopicsArrayMath |
| Remove Duplicates from Sorted Array II | Medium | 49% | TopicsArrayTwo Pointers |
| Basic Calculator II | Medium | 49% | TopicsMathStringStack |
| Decode String | Medium | 49% | TopicsStringStackRecursion |
| 3434. Maximum Frequency After Subarray Operation | Medium | 49% | TopicsArrayHash TableDynamic ProgrammingGreedyEnumerationPrefix Sum |
| Minimum Size Subarray Sum | Medium | 48.6% | TopicsArrayBinary SearchSliding WindowPrefix Sum |
| 219. Contains Duplicate II | Easy | 48.6% | TopicsArrayHash TableSliding Window |
| 349. Intersection of Two Arrays | Easy | 48.6% | TopicsArrayHash TableTwo PointersBinary SearchSorting |
| 981. Time Based Key-Value Store | Medium | 48.6% | TopicsHash TableStringBinary SearchDesign |
| Find Minimum in Rotated Sorted Array | Medium | 48.2% | TopicsArrayBinary Search |
| 37. Sudoku Solver | Hard | 47.8% | TopicsArrayHash TableBacktrackingMatrixAlgorithm XDancing Links |
| 101. Symmetric Tree | Easy | 47.8% | TopicsTreeDepth-First SearchBreadth-First SearchBinary Tree |
| Second Highest Salary | Medium | 47.8% | TopicsDatabase |
| 204. Count Primes | Medium | 47.8% | TopicsArrayMathEnumerationNumber TheoryPrimality TestSieve TheoryPrime Number Sieve |
| 205. Isomorphic Strings | Easy | 47.8% | TopicsHash TableString |
| Integer to English Words | Hard | 47.8% | TopicsMathStringRecursion |
| 973. K Closest Points to Origin | Medium | 47.8% | TopicsArrayMathDivide and ConquerGeometrySortingHeap (Priority Queue)QuickselectK-D Tree |
| 987. Vertical Order Traversal of a Binary Tree | Hard | 47.8% | TopicsHash TableTreeDepth-First SearchBreadth-First SearchSortingBinary Tree |
| 796. Rotate String | Easy | 47.4% | TopicsStringString Matching |
