# ---
# title: 1448. Count Good Nodes in Binary Tree
# id: problem1448
# author: Tian Jun
# date: 2020-10-31
# difficulty: Medium
# categories: Tree, Depth-first Search
# link: <https://leetcode.com/problems/count-good-nodes-in-binary-tree/description/>
# hidden: true
# ---
# 
# Given a binary tree `root`, a node _X_ in the tree is named  **good** if in
# the path from root to _X_ there are no nodes with a value _greater than_ X.
# 
# Return the number of **good** nodes in the binary tree.
# 
# 
# 
# **Example 1:**
# 
# **![](https://assets.leetcode.com/uploads/2020/04/02/test_sample_1.png)**
# 
#     
#     
#     Input: root = [3,1,4,3,null,1,5]
#     Output: 4
#     Explanation: Nodes in blue are **good**.
#     Root Node (3) is always a good node.
#     Node 4 -> (3,4) is the maximum value in the path starting from the root.
#     Node 5 -> (3,4,5) is the maximum value in the path
#     Node 3 -> (3,1,3) is the maximum value in the path.
# 
# **Example 2:**
# 
# **![](https://assets.leetcode.com/uploads/2020/04/02/test_sample_2.png)**
# 
#     
#     
#     Input: root = [3,3,null,4,2]
#     Output: 3
#     Explanation: Node 2 -> (3, 3, 2) is not good, because "3" is higher than it.
# 
# **Example 3:**
# 
#     
#     
#     Input: root = [1]
#     Output: 1
#     Explanation: Root is considered as **good**.
# 
# 
# 
# **Constraints:**
# 
#   * The number of nodes in the binary tree is in the range `[1, 10^5]`.
#   * Each node's value is between `[-10^4, 10^4]`.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
