binary-search-tree-to-greater-sum-tree.md

<p>Given the root of a binary <strong>search</strong> tree with distinct values, modify it so that every <code>node</code>&nbsp;has a new value equal to the sum of the values of the original tree that are greater than or equal to <code>node.val</code>.</p>

<p>As a reminder, a&nbsp;<em>binary search tree</em> is a tree that satisfies these constraints:</p>

<ul>
	<li>The left subtree of a node contains only nodes with keys&nbsp;<strong>less than</strong>&nbsp;the node&#39;s key.</li>
	<li>The right subtree of a node contains only nodes with keys&nbsp;<strong>greater than</strong>&nbsp;the node&#39;s key.</li>
	<li>Both the left and right subtrees must also be binary search trees.</li>
</ul>

<p>&nbsp;</p>

<p><strong>Example 1:</strong></p>

<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2019/05/02/tree.png" style="width: 280px; height: 191px;" /></strong></p>

<pre>
<strong>Input: </strong><span id="example-input-1-1">[4,1,6,0,2,5,7,null,null,null,3,null,null,null,8]</span>
<strong>Output: </strong><span id="example-output-1">[30,36,21,36,35,26,15,null,null,null,33,null,null,null,8]</span>
</pre>

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<p>&nbsp;</p>
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<p><strong>Note:</strong></p>

<ol>
	<li>The number of nodes in the tree is between <code>1</code> and <code>100</code>.</li>
	<li>Each node will have value between <code>0</code> and <code>100</code>.</li>
	<li>The given tree is a binary search tree.</li>
</ol>

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