cpp-flashcards/org/study_deck_02/dsa/trees/1448-count-good-nodes-in-binary-tree.org

#+ANKI_DECK: study_deck_02
* TODO 1448. Count Good Nodes In Binary Tree :medium:
:PROPERTIES:
:NEETCODE: [[file:../../roadmap.org::*1448. Count Good Nodes In Binary Tree][1448. Count Good Nodes In Binary Tree]]
:END:

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:*

**


#+begin_src
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.
#+end_src


*Example 2:*

**


#+begin_src
Input: root = [3,3,null,4,2]
Output: 3
Explanation: Node 2 -> (3, 3, 2) is not good, because "3" is higher than it.
#+end_src


*Example 3:*


#+begin_src
Input: root = [1]
Output: 1
Explanation: Root is considered as good.
#+end_src


*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]~.

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python :lc-problem 1448 :lc-lang python3
# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def goodNodes(self, root: TreeNode) -> int:
#+end_src

** TODO C++
#+begin_src cpp :lc-problem 1448
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    int goodNodes(TreeNode* root) {
        
    }
};
#+end_src