About This Pattern
Master the DFS / Combinatorics pattern by practicing these problems organized by difficulty.Focus on the Key Signals - these are the indicators that tell you when to use this pattern.
Hard (1)
Number of Ways to Reorder Array to Get Same BST
Given an array representing BST insertion order, return number of arrays that would yield the same BST.
Key Signals:
Tree constructionCounting permutationsRecursion