> For the complete documentation index, see [llms.txt](https://zedive.gitbook.io/project-l/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zedive.gitbook.io/project-l/part-1/basic_data_structure/binary_tree/binary_search_tree/search-in-a-binary-search-tree.md).

# Search in a Binary Search Tree

## Question ([LC.700](https://leetcode.com/problems/search-in-a-binary-search-tree/)) 

> Given the root of a BST and a target value, find the node with the corresponding value. 

## Example 

```
I: Given the root 4, target value is 2 
        4
       / \
      2   7
     / \
    1   3

O: 
      2     
     / \   
    1   3
```

## Analysis 

Searching a balanced BST is fast. O(logn) time. 

## Code 

```python
def searchBST(self, root: TreeNode, val: int) -> TreeNode:
    
    if root is None:
        return None 
    
    if root.val == val:
        return root 
    
    if val >= root.val:
        return self.searchBST(root.right, val)
    else:
        return self.searchBST(root.left, val)

```


---

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