leetcode_998. Maximum Binary Tree II

https://leetcode.com/problems/maximum-binary-tree-ii/

在654. Maximum Binary Tree版本的建树基础上，在最后插入一个数。

新节点要么为根节点，原树为其左子树；要么将新节点插在右子树中。

class Solution
{
public:
    TreeNode* insertIntoMaxTree(TreeNode* root, int val)
    {
        if(root == NULL)
        {
            root = new TreeNode(val);
            return root;
        }
        if(val > root->val)
        {
            TreeNode* temporary = root;
            root = new TreeNode(val);
            root->left = temporary;
            return root;
        }
        else
        {
            root->right = insertIntoMaxTree(root->right, val);
            return root;
        }
    }
};