# DIY: All Nodes Distance K in Binary Tree

Solve the interview question "All Nodes Distance K in Binary Tree" in this lesson.

We'll cover the following

## Problem statement

We are given a binary tree (with a root node root), a target node, and an integer value, kk.

Return a list of the values of all nodes that are kk distance from the target node.

### Input

The following is an example input:

    3
/ \
5   1
|  /  \
2 15   7
/ \
7   4

target = 5
kk = 2


### Output

The following is an example output:

[7,4,1]


The nodes that are a distance 2 from the target node 5 have the values 7, 4, and 1.

## Coding exercise

For this coding exercise, you need to implement the distance_k(root, target, kk) function, where root is the root node of the binary tree and target is where we start calculating the distance kk. The function will return a list of the values of all the nodes that are kk distance from the target node.

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