1function TreeNode(val, left, right) {
2    this.val = (val===undefined ? 0 : val)
3    this.left = (left===undefined ? null : left)
4    this.right = (right===undefined ? null : right)
5}
6
7const goodNodes = function(root) {
8    const dfs = (node, maxVal) => {
9        if (!node) return 0;
10        let good = 0;
11        if (node.val >= maxVal) good = 1;
12        maxVal = Math.max(maxVal, node.val);
13        good += dfs(node.left, maxVal);
14        good += dfs(node.right, maxVal);
15        return good;
16    };
17    return dfs(root, root.val);
18};
19

using System.Collections.Generic;

public class TreeNode {
    public int val;
    public TreeNode left;
    public TreeNode right;
    public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}

public class Solution {
    public int GoodNodes(TreeNode root) {
        if (root == null) return 0;
        Queue<(TreeNode, int)> queue = new Queue<(TreeNode, int)>();
        queue.Enqueue((root, root.val));
        int goodCount = 0;
        while (queue.Count > 0) {
            (TreeNode node, int maxVal) = queue.Dequeue();
            if (node.val >= maxVal) goodCount++;
            if (node.left != null) queue.Enqueue((node.left, Math.Max(maxVal, node.val)));
            if (node.right != null) queue.Enqueue((node.right, Math.Max(maxVal, node.val)));
        }
        return goodCount;
    }
}