two-sum-iv-input-is-a-bst.md

<p>Given a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target.</p>

<p><b>Example 1:</b></p>

<pre>
<b>Input:</b> 
    5
   / \
  3   6
 / \   \
2   4   7

Target = 9

<b>Output:</b> True
</pre>

<p>&nbsp;</p>

<p><b>Example 2:</b></p>

<pre>
<b>Input:</b> 
    5
   / \
  3   6
 / \   \
2   4   7

Target = 28

<b>Output:</b> False
</pre>

<p>&nbsp;</p>