Validate Binary Search Tree
Return true if the binary tree is a valid BST Example: [2,1,3] => True
Validate Binary Search Tree is a traversal problem: the hard part is modeling the state you visit. Interviewers love it because it reveals your traversal modeling and your edge-case discipline. Once your traversal structure is solid, you can reuse it across dozens of problems.
Meet Coco
Coco is an AI study partner, not a person. She listens while you explain your code, asks what a line does and never hands you the fix. Sign in free to type with Coco, up to a daily limit, and to talk with her for one hour. After that, talking comes with the $79 pack. Anyone can open the editor and run their code.
Each locked part opens in the editor once the part before it passes.
Prep guides that list this problem
Our company tags come from public interview write-ups. None of these is a confirmed question.