How should I practice All Nodes Distance K in a Binary Tree?

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

Is All Nodes Distance K in a Binary Tree associated with Amazon?

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

Problem · Tree

All Nodes Distance K in a Binary Tree

Learn this problem

● Medium

AmazonFULLTIMEPHONE SCREEN

See Amazon hiring insights

Problem statement

You are given the root of a binary tree whose node values are unique, an integer target equal to one node value, and a nonnegative integer k.

Two directly connected tree nodes are one edge apart. Return the values of every node whose shortest-path distance from the target node is exactly k.

Return the values in ascending order. If no node is exactly k edges away, return an empty list.

Function

distanceK(root: TreeNode, target: int, k: int) → List<Integer>

Examples

Example 1

root = [3,5,1,6,2,0,8,null,null,7,4]target = 5k = 2return = [1,4,7]

From node 5, nodes 7 and 4 are reached through node 2, while node 1 is reached through node 3. Each is two edges away.

Example 2

root = [1]target = 1k = 0return = [1]

The target node itself is the only node at distance 0.

Constraints

The tree contains between 1 and 500 nodes.
0 <= Node.val <= 500.
Every node value is unique.
target is the value of a node in the tree.
0 <= k <= 1000.