balanced-binary-tree.md

<p>Given a binary tree, determine if it is height-balanced.</p>

<p>For this problem, a height-balanced binary tree is defined as:</p>

<blockquote>
<p>a binary tree in which the left and right subtrees of <em>every</em> node differ in height by no more than 1.</p>
</blockquote>

<p>&nbsp;</p>

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

<p>Given the following tree <code>[3,9,20,null,null,15,7]</code>:</p>

<pre>
    3
   / \
  9  20
    /  \
   15   7</pre>

<p>Return true.<br />
<br />
<strong>Example 2:</strong></p>

<p>Given the following tree <code>[1,2,2,3,3,null,null,4,4]</code>:</p>

<pre>
       1
      / \
     2   2
    / \
   3   3
  / \
 4   4
</pre>

<p>Return false.</p>