Login

Top Apple Coding Interview Questions

Problem title

Difficulty

Avg time to solve

Maximum Size Rectangle Sub-matrix With All 1's

Hard

10 mins

Minimum Number Of Taps To Water Garden

Hard

15 mins

Morse Code To English

Easy

15 mins

Print Nodes at Distance K From a Given Node

Hard

20 mins

Spiral Matrix

Easy

15 mins

Inplace rotate matrix 90 degree

Easy

12 mins

House Robber

Moderate

15 mins

Merge Two Sorted Linked Lists

Moderate

15 mins

Palindrome Partitioning

Hard

25 mins

Right View

Moderate

35 mins

Problem

Submissions

3

Avg. time to solve

20 min

Success Rate

80%

Problem Statement

```
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 there are no nodes in the tree which 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. For example if the valid nodes have values 1,2,3, then you can return {1,2,3} or {3,1,2} etc.
```

```
The first line of the input contains an integer T, denoting the number of test cases to run.
The first line of each test case will contain the values of the nodes of the tree in the level order form ( -1 for NULL node). Refer to the example below for further explanation.
The second line of each test case contains the value of the target node.
The third and the last line of each test case contains the integer K denoting the distance at which nodes are to be found.
Example:
Consider the binary tree:
```

```
The input for the tree depicted in the above image would be :
3
5 1
6 2 0 8
-1 -1 7 4 -1 -1 -1 -1
-1 -1 -1 -1
Explanation :
Level 1 :
The root node of the tree is 3
Level 2 :
Left child of 3 = 5
Right child of 3 = 1
Level 3 :
Left child of 5 = 6
Right child of 5 = 2
Left child of 1 = 0
Right child of 1 = 8
Level 4 :
Left child of 6 = null (-1)
Right child of 6 = null(-1)
Left child of 2 = 7
Right child of 2 = 4
Left child of 0 = null (-1)
Right child of 0 = null (-1)
Left child of 8 = null (-1)
Right child of 8 = null (-1)
Level 5 :
Left child of 7 = null (-1)
Right child of 7 = null (-1)
Left child of 4 = null (-1)
Right child of 4 = null (-1)
The first not-null node (of the previous level) is treated as the parent of the first two nodes of the current level. The second not-null node (of the previous level) is treated as the parent node for the next two nodes of the current level and so on.
The input ends when all nodes at the last level are null (-1).
```

```
For each test case, print the values of all nodes at distance = K, from the given target node.
```

```
You do not need to print anything, it has already been taken care of. Just implement the given function.
```

```
1 <= T <= 100
1 <= N <= 3000
0 <= K <= 3000
0 <= nodeValue <= 3000
Where nodeValue donates the value of the node.
Time Limit: 1 sec
```

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

```
7 4 1
```

```
Target Node is 5. Nodes at distance 1 from 5 are {6, 2, 3} and nodes at distance 2 are {7, 4, 1}.
```

```
1
1 2 3 4 5 -1 -1 6 -1 -1 -1 -1 -1
5
3
```

```
6 3
```

```
The tree will be generated as above. The target node is 5 and K = 3. The nodes at distance 1 from node 5 are {2}, nodes at distance 2 from node 5 are {1, 4} and nodes at distance 3 from node 5 are {6, 3}.
```

Console

Sample Test Case

Custom Test Case

Download Test Cases

Test Case 1

Test Case 2

Test Case 3

Saving Code...

Full Screen Mode

Change Language

Change Theme

Solution submission not allowed

Save Code

Reset Code