Count Good Nodes in Binary Tree
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
3
/ \
1 4
/ / \
3 1 5Input
root = [3,1,4,3,null,1,5]Output
4Root node 3 is always good, node 4 is the maximum on path (3, 4), node 5 is the maximum on path (3, 4, 5), and node 3 is the maximum on path (3, 1, 3).
Example 2
3
/
3
/ \
4 2Input
root = [3,3,null,4,2]Output
3Node 2 on path (3, 3, 2) is not good because 3 is greater than it.
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].