Practice problems across 75+ categories
Practice problems frequently asked at Stack • 172 problems | 23 Easy | 97 Medium | 51 Hard
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 166 | Tag Validator | Hard | StringStack |
| 167 | Tarjan's Strongly Connected Components | Hard | Advanced GraphsGraphDFS |
| 168 | Temperature Tracker | Medium | ArraysArrayStack |
| 169 | Ternary Expression Parser | Medium | StringStackRecursion |
| 170 | The Number of Weak Characters in the Game | Medium | ArrayStackGreedy |
| 171 | The Score of Students Solving Math Expression | Hard | ArrayHash TableMath |
| 172 | Trapping Rain Water | Hard | ArrayTwo PointersDynamic Programming |
| 173 | Two Sum BSTs | Medium | Two PointersBinary SearchStack |
| 174 | Undo Text Editor | Easy | Data StructuresStackString |
| 175 | Using a Robot to Print the Lexicographically Smallest String | Medium | Hash TableStringStack |
| 176 | Valid Parentheses | Easy | StringStack |
| 177 | Valid Parenthesis String | Medium | StringDynamic ProgrammingStack |
| 178 | Validate Stack Sequences | Medium | ArrayStackSimulation |
| 179 | Verify Preorder Sequence in Binary Search Tree | Medium | ArrayStackTree |
| 180 | Verify Preorder Serialization of a Binary Tree | Medium | StringStackTree |
Powerful online tools to boost your productivity
Coding Ground For Developers
Code, Edit, Run and ShareIgnite your coding potential on Coding Ground - an immersive online platform for hands-on learning, collaboration, and skill development.
