1448. 统计二叉树中好节点的数目

1448. 统计二叉树中好节点的数目

题目链接：1448. 统计二叉树中好节点的数目

代码如下：

/**
 * 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:
    //参考:https://leetcode.cn/problems/count-good-nodes-in-binary-tree/solutions/2403677/jian-ji-xie-fa-pythonjavacgojs-by-endles-gwxt
    int goodNodes(TreeNode* root,int mx=INT_MIN) 
    {
        if(root==nullptr)   return 0;
        int left=goodNodes(root->left,max(mx,root->val));
        int right=goodNodes(root->right,max(mx,root->val));
        return left+right+(mx<=root->val);
    }
};