leetcode-700：二叉搜索树中的搜索

给定二叉搜索树:
        4
       / \
      2   7
     / \
    1   3
和值: 2

2     
     / \   
    1   3

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def searchBST(self, root: TreeNode, val: int) -> TreeNode:
        cur = root
        while cur:
            if val<cur.val:
                cur = cur.left
            elif val>cur.val:
                cur = cur.right
            else:
                return cur
        return None

class Solution {
public:
    TreeNode* searchBST(TreeNode* root, int val) {
        TreeNode* cur=root;
        while(cur){
            if(cur->val==val) return cur;
            else if(cur->val<val) cur=cur->right;
            else cur=cur->left;
        }
        return nullptr;
    }
};

class Solution {
    public TreeNode searchBST(TreeNode root, int val) {
        TreeNode cur=root;
        while(cur!=null){
            if(val==cur.val) return cur;
            else if(val>cur.val){
                cur=cur.right;
            }else{
                cur=cur.left;
            }
        }
        return null;
    }
}