Print Nodes at Distance K from a Given Node

Given an arbitrary binary tree, a node of the tree, and an integer 'K', find all nodes that are at a distance K from the specified node, and return a list of these nodes.

The distance between two nodes in a binary tree is defined as the number of connections/edges in the path between the two nodes.

Input:

The first line of the input contains an integer T, denoting the number of test cases to run.

For each test case:
- The first line contains the values of the nodes of the tree in level order format (-1 representing a NULL node).
- The second line contains the value of the target node.
- The third line contains the integer K, representing the distance at which nodes are to be found.

Output:

For each test case, output the values of all nodes at distance = K from the specified target node.

Example:

The input example for the tree could be:

3
5 1
6 2 0 8
-1 -1 7 4 -1 -1 -1 -1
-1 -1 -1 -1

target: 5
K: 1

Output:
1 6 2

Constraints:

• 1 <= T <= 100
• 1 <= N <= 3000
• 0 <= K <= 3000
• 0 <= nodeValue <= 3000
• Time Limit: 1 sec

Note:

1. A binary tree is a tree in which each node has at most two children.
2. The given tree will be non-empty.
3. The given tree can have multiple nodes with the same value.
4. If no nodes are at distance K from the given node, return an empty list.
5. You can return the list of values of valid nodes in any order.