632. Binary Tree Maximum Node【Naive】

Find the maximum node in a binary tree, return the node.

Example

Given a binary tree:

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

return the node with value 3.

 

解法一：

 

class Solution {
public:
    /**
     * @param root the root of binary tree
     * @return the max node
     */
    TreeNode* maxNode(TreeNode* root) {
        // Write your code here
        if (root == NULL) {
            return root;    
        }

        TreeNode* left = maxNode(root->left);
        TreeNode* right = maxNode(root->right);

        return max(root, max(left, right));
    }
    
    TreeNode* max(TreeNode* a, TreeNode* b) {
        if (a == NULL || b == NULL) {
            return (a == NULL ? b : a);            
        }
        
        return (a->val > b->val ? a : b);     
    }

    
};