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);
     }

 };