Amazon
2015 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| 3639. Minimum Time to Activate String | Medium | 21.9% | TopicsArrayBinary Search |
| 3627. Maximum Median Sum of Subsequences of Size 3 | Medium | 21.9% | TopicsArrayMathGreedySortingGame Theory |
| 940. Distinct Subsequences II | Hard | 21.9% | TopicsStringDynamic Programming |
| 2910. Minimum Number of Groups to Create a Valid Assignment | Medium | 21.9% | TopicsArrayHash TableGreedy |
| 3786. Total Sum of Interaction Cost in Tree Groups | Hard | 21.9% | TopicsArrayTreeDepth-First Search |
| 3922. Minimum Flips to Make Binary String Coherent | Medium | 21.9% | TopicsString |
| 3989. Maximum Consistent Columns in a Grid | Hard | 21.9% | TopicsArrayDynamic ProgrammingMatrix |
| 4012. Count of Unfinished Tasks After Each Shift | Medium | 21.9% | TopicsArrayBinary SearchPrefix Sum |
| 1111. Maximum Nesting Depth of Two Valid Parentheses Strings | Medium | 21.9% | TopicsStringStackBracket Sequences |
| Scramble String | Hard | 20.1% | TopicsStringDynamic Programming |
| Construct Binary Tree from Inorder and Postorder Traversal | Medium | 20.1% | TopicsArrayHash TableDivide and ConquerTreeBinary Tree |
| Factorial Trailing Zeroes | Medium | 20.1% | TopicsMath |
| Valid Phone Numbers | Easy | 20.1% | TopicsShell |
| Count Complete Tree Nodes | Medium | 20.1% | TopicsBinary SearchBit ManipulationTreeBinary Tree |
| Encode and Decode Strings | Medium | 20.1% | TopicsArrayStringDesign |
| Range Sum Query 2D - Immutable | Medium | 20.1% | TopicsArrayDesignMatrixPrefix Sum |
| 327. Count of Range Sum | Hard | 20.1% | TopicsArrayBinary SearchDivide and ConquerBinary Indexed TreeSegment TreeMerge SortOrdered SetTreap |
| Island Perimeter | Easy | 20.1% | TopicsArrayDepth-First SearchBreadth-First SearchMatrix |
| 465. Optimal Account Balancing | Hard | 20.1% | TopicsArrayDynamic ProgrammingBacktrackingBit ManipulationBitmask |
| Construct Binary Tree from String | Medium | 20.1% | TopicsStringStackTreeDepth-First SearchBinary Tree |
| Complex Number Multiplication | Medium | 20.1% | TopicsMathStringSimulation |
| Find Cumulative Salary of an Employee | Hard | 20.1% | TopicsDatabase |
| Find Duplicate Subtrees | Medium | 20.1% | TopicsHash TableTreeDepth-First SearchBinary Tree |
| Equal Tree Partition | Medium | 20.1% | TopicsTreeDepth-First SearchBinary Tree |
| Trim a Binary Search Tree | Medium | 20.1% | TopicsTreeDepth-First SearchBinary Search TreeBinary Tree |
