intersection-of-two-arrays-ii.md

<p>Given two arrays, write a function to compute their intersection.</p>

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

<pre>
<strong>Input: </strong>nums1 = <span id="example-input-1-1">[1,2,2,1]</span>, nums2 = <span id="example-input-1-2">[2,2]</span>
<strong>Output: </strong><span id="example-output-1">[2,2]</span>
</pre>

<div>
<p><strong>Example 2:</strong></p>

<pre>
<strong>Input: </strong>nums1 = <span id="example-input-2-1">[4,9,5]</span>, nums2 = <span id="example-input-2-2">[9,4,9,8,4]</span>
<strong>Output: </strong><span id="example-output-2">[4,9]</span></pre>
</div>

<p><b>Note:</b></p>

<ul>
	<li>Each element in the result should appear as many times as it shows in both arrays.</li>
	<li>The result can be in any order.</li>
</ul>

<p><b>Follow up:</b></p>

<ul>
	<li>What if the given array is already sorted? How would you optimize your algorithm?</li>
	<li>What if <i>nums1</i>&#39;s size is small compared to <i>nums2</i>&#39;s size? Which algorithm is better?</li>
	<li>What if elements of <i>nums2</i> are stored on disk, and the memory is limited such that you cannot load all elements into the memory at once?</li>
</ul>