BlackRock
10 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| 202. Happy Number | Easy | 100% | TopicsHash TableMathTwo PointersFloyd's Cycle Finding Algorithm |
| 20. Valid Parentheses | Easy | 90.5% | TopicsStringStackBracket Sequences |
| 235. Lowest Common Ancestor of a Binary Search Tree | Medium | 67.8% | TopicsTreeDepth-First SearchBinary Search TreeBinary TreeBinary LiftingLowest Common Ancestor |
| 49. Group Anagrams | Medium | 64.3% | TopicsArrayHash TableStringSorting |
| Lowest Common Ancestor of a Binary Tree | Medium | 60.1% | TopicsTreeDepth-First SearchBinary TreeBinary LiftingLowest Common Ancestor |
| 3998. Transform Binary String Using Subsequence Sort | Medium | 54.7% | TopicsArrayTwo PointersStringGreedy |
| 121. Best Time to Buy and Sell Stock | Easy | 47.1% | TopicsArrayDynamic Programming |
| 1. Two Sum | Easy | 47.1% | TopicsArrayHash Table |
| 70. Climbing Stairs | Easy | 47.1% | TopicsMathDynamic ProgrammingMemoization |
| 12. Integer to Roman | Medium | 47.1% | TopicsHash TableMathString |
