【树】700. 二叉搜索树中的搜索

题目：

 

 

 

解答:

方法一：递归

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12      TreeNode* searchBST(TreeNode* root, int val) 
13      {
14         if(!root || root->val == val) 
15         {
16             return root;
17         }
18         
19         return root->val > val ? searchBST(root->left, val) : searchBST(root->right, val);
20     }
21 };

 

方法二：迭代

 1 /**
 2  * Definition for a binary tree node.
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     TreeNode* searchBST(TreeNode* root, int val) 
13     {
14         while(true)
15         {
16             if(!root || root->val == val) 
17             {
18                 return root;
19             }
20             root = root->val > val ? root->left : root->right;
21         }
22     }
23 };

 

posted @ 2020-05-03 15:04  梦醒潇湘  阅读(128)  评论(0)    收藏  举报