LintCode:在二叉查找树中插入节点

[LintCode:在二叉查找树中插入节点](http://www.lintcode.com/zh-cn/problem/insert-node-in-a-binary-search-tree/)

Python

""" Definition of TreeNode: class TreeNode: def __init__(self, val): self.val = val self.left, self.right = None, None """
class Solution:
    """ @param root: The root of the binary search tree. @param node: insert this node into the binary search tree. @return: The root of the new binary search tree. """
    def insertNode(self, root, node):
        # write your code here
        if root == None:
            return node
        self.pre_order(root, node)
        return root

    def pre_order(self, root, node):
        if node.val > root.val:
            if root.right == None:
                root.right = node
                return
            self.pre_order(root.right, node)
        else:
            if root.left == None:
                root.left = node
                return
            self.pre_order(root.left, node)

Java

/** * Definition of TreeNode: * public class TreeNode { * public int val; * public TreeNode left, right; * public TreeNode(int val) { * this.val = val; * this.left = this.right = null; * } * } */
public class Solution {
    /** * @param root: The root of the binary search tree. * @param node: insert this node into the binary search tree * @return: The root of the new binary search tree. */
    public TreeNode insertNode(TreeNode root, TreeNode node) {
        // write your code here
        if (root == null){
            return node;
        }
        preOrder(root, node);
        return root;
    }

    private static void preOrder(TreeNode root, TreeNode node){
        if(node.val > root.val){
            if (root.right == null){
                root.right = node;
                return;
            }
            preOrder(root.right, node);
        }
        else{
            if (root.left == null){
                root.left = node;
                return;
            }
            preOrder(root.left, node);
        }

    }
}