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.
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.
Input: root = [3,3,null,4,2] Output: 3 Explanation: Node 2 -> (3, 3, 2) is not good, because "3" is higher than it.
Input: root =  Output: 1 Explanation: Root is considered as good.
- The number of nodes in the binary tree is in the range
- Each node’s value is between
# 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 count = 0 def traversal(root,mx): global count if root==None:return mx = max(root.val,mx) if root.val>=mx: count+=1 traversal(root.left,mx) traversal(root.right,mx) class Solution: def goodNodes(self, root: TreeNode) -> int: global count count = 0 mx = root.val traversal(root,mx) return count