1#include <iostream>
2using namespace std;
3
4struct TreeNode {
5    int val;
6    TreeNode *left;
7    TreeNode *right;
8    TreeNode() : val(0), left(nullptr), right(nullptr) {}
9    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
10    TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
11};
12
13class Solution {
14public:
15    int dfs(TreeNode* node, int maxVal) {
16        if (!node) return 0;
17        int good = 0;
18        if (node->val >= maxVal) good = 1;
19        maxVal = max(maxVal, node->val);
20        return good + dfs(node->left, maxVal) + dfs(node->right, maxVal);
21    }
22
23    int goodNodes(TreeNode* root) {
24        return dfs(root, root->val);
25    }
26};
27

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;
    }
}