How should I practice Create a Binary Tree from Parent-Child Descriptions?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Amazon phone screen problems in FastPrep.

Is Create a Binary Tree from Parent-Child Descriptions associated with Amazon?

FastPrep tags this as a Amazon phone screen coding practice problem when the problem catalog has that company and stage context.

Amazon● MediumNEW GRADPHONE SCREEN

You are given an array descriptions. Each entry has the form [parent, child, isLeft] and describes one edge in a binary tree:

The descriptions may appear in any order, so an entry can mention a child before the entry that connects its parent to the rest of the tree.

Build the described binary tree and return its root.

createBinaryTree(descriptions: int[][]) → TreeNode

descriptions = [[20,15,1],[20,17,0],[50,20,1],[50,80,0],[80,19,1]]return = [50,20,80,15,17,19]

50 is the only value that never appears as a child. Its children are 20 and 80; the remaining descriptions attach 15, 17, and 19.

descriptions = [[3,4,1],[1,2,1],[1,3,0]]return = [1,2,3,null,null,4]

The first description initially forms a separate subtree rooted at 3. The last description connects that subtree as the right child of 1.

descriptions is non-empty.
Every entry contains exactly three integers in the form [parent, child, isLeft].
isLeft is either 0 or 1.
Node values uniquely identify nodes.
The descriptions define exactly one valid, non-empty binary tree.