leetcode-26双周赛-5398-统计二叉树中好结点的数目

题目描述：

 

 提交：

class Solution:
    def goodNodes(self, root: TreeNode) -> int:
        def helper(m,node):
            r,left,right = 0,0,0
            if node.val >= m:
                r = 1
            if node.left:
                left = helper(max(m,node.val),node.left)
            if node.right:
                right = helper(max(m,node.val),node.right)
            return r + left + right
        
        if not root:
            return 0
        return helper(root.val,root)