Amazon
2015 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| Range Sum Query - Immutable | Easy | 37.5% | TopicsArrayDesignPrefix Sum |
| 312. Burst Balloons | Hard | 37.5% | TopicsArrayDynamic Programming |
| Remove Duplicate Letters | Medium | 37.5% | TopicsStringStackGreedyMonotonic Stack |
| Smallest Range Covering Elements from K Lists | Hard | 37.5% | TopicsArrayHash TableGreedySliding WindowSortingHeap (Priority Queue) |
| 678. Valid Parenthesis String | Medium | 37.5% | TopicsStringDynamic ProgrammingStackGreedyBracket Sequences |
| 1091. Shortest Path in Binary Matrix | Medium | 37.5% | TopicsArrayBreadth-First SearchMatrix |
| Customer Who Visited but Did Not Make Any Transactions | Easy | 37.5% | TopicsDatabase |
| 1922. Count Good Numbers | Medium | 37.5% | TopicsMathRecursion |
| 2163. Minimum Difference in Sums After Removal of Elements | Hard | 37.5% | TopicsArrayDynamic ProgrammingHeap (Priority Queue) |
| 3644. Maximum K to Sort a Permutation | Medium | 37.5% | TopicsArrayBit Manipulation |
| 3752. Lexicographically Smallest Negated Permutation that Sums to Target | Medium | 37.5% | TopicsArrayMathTwo PointersGreedySorting |
| Substring with Concatenation of All Words | Hard | 36.7% | TopicsHash TableStringSliding Window |
| Multiply Strings | Medium | 36.7% | TopicsMathStringSimulation |
| 91. Decode Ways | Medium | 36.7% | TopicsStringDynamic Programming |
| Single Number II | Medium | 36.7% | TopicsArrayBit Manipulation |
| Implement Trie (Prefix Tree) | Medium | 36.7% | TopicsHash TableStringDesignTrie |
| Implement Queue using Stacks | Easy | 36.7% | TopicsStackDesignQueue |
| 258. Add Digits | Easy | 36.7% | TopicsMathSimulationNumber Theory |
| Alien Dictionary | Hard | 36.7% | TopicsArrayStringDepth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph |
| Delete Node in a BST | Medium | 36.7% | TopicsTreeBinary Search TreeBinary Tree |
| Diagonal Traverse | Medium | 36.7% | TopicsArrayMatrixSimulation |
| Coin Change II | Medium | 36.7% | TopicsArrayDynamic ProgrammingKnapsack ProblemComplete Knapsack |
| 724. Find Pivot Index | Easy | 36.7% | TopicsArrayPrefix Sum |
| 785. Is Graph Bipartite? | Medium | 36.7% | TopicsDepth-First SearchBreadth-First SearchUnion-FindGraph TheoryGraph ColoringBipartite Graph |
| 968. Binary Tree Cameras | Hard | 36.7% | TopicsDynamic ProgrammingTreeDepth-First SearchBinary TreeDP on Trees |
