All Nodes Distance K in Binary Tree

Problem statement

Given the root of a binary tree, the value of a target node target, and an integer k, return an array of the values of all nodes that have a distance k from the target node.

You can return the answer in any order.

Example 1:

Input: root = [3,5,1,6,2,0,8,null,null,7,4], target = 5, k = 2Output: [7,4,1]Explanation: The nodes that are a distance 2 from the target node (with value 5) have values 7, 4, and 1.

Example 2:

Input: root = [1], target = 1, k = 3Output: []

Constraints:

• The number of nodes in the tree is in the range [1, 500].
• 0 <= Node.val <= 500
• All the values Node.val are unique.
• target is the value of one of the nodes in the tree.
• 0 <= k <= 1000

My solution

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @param {TreeNode} target
 * @param {number} k
 * @return {number[]}
 */
var distanceK = function(root, target, k) {
    const nodes = [];
    
    if (k === 0) {
        return [target.val]
    }
    
    function findTargetNode(node, parent = null) {
        if (!node) {
            return;
        }
        
        node.parent = parent;
        
        if (node.val === target.val) {
            return node;
        }
        
        return findTargetNode(node.left, node) || findTargetNode(node.right, node)
    }
    
    const targetNode = findTargetNode(root)
    
    function findNodeAtDistance(node, distance) {
        if (!node || distance < 0 || node.visited) {
            return;
        }
        
        node.visited = true;
        
        if (distance === 0 && node.val !== targetNode.val) {
            nodes.push(node.val);
            return;
        }
        
        findNodeAtDistance(node.parent, distance - 1);
        findNodeAtDistance(node.left, distance - 1);
        findNodeAtDistance(node.right, distance - 1);
    }

    findNodeAtDistance(targetNode, k)
    
    return nodes;
    
};