在二叉樹中尋找值最大的節點並返回。

樣例

給出如下一棵二叉樹：

     1
   /   \
 -5     2
 / \   /  \
0   3 -4  -5 

返回值為 3 的節點。

python：

class Solution:
    """
    @param: root: the root of tree
    @return: the max node
    """
    def maxNode(self, root):
        # write your code here
        if root is None:
            return
        self.max(root)
        return self.node
    maxVal = -9999
    node = None
    def max(self, root):
        if root is None:
            return
        if root.val >= self.maxVal:
            self.maxVal = root.val
            self.node = root
        self.max(root.left)
        self.max(root.right)
 

C++：

class Solution {
public:
    /*
     * @param root: the root of tree
     * @return: the max node
     */
    int maxx=-99999;
    TreeNode *pmax;
    void max(TreeNode *root)
    {
        if(root==NULL)
            return ;
        if(root->val>maxx)
        {
            maxx=root->val;
            pmax=root;
        }
        max(root->left);
        max(root->right);
    }
    TreeNode * maxNode(TreeNode * root) {
        // write your code here
        if(root==NULL)
            return NULL;
        max(root);
        return pmax;
    }

};