merge sorted list<int>
<p>I have two already sorted <code>List&lt;int&gt;</code>, how do I efficiently merge them into just one sorted list?</p>

<p>For example:</p>

<pre><code>List&lt;int&gt; a = new List&lt;int&gt;() {1, 2, 3};
List&lt;int&gt; b = new List&lt;int&gt;() {1, 4, 5};
List&lt;int&gt; aAndB = ....?
</code></pre>

<p>I would like that my <code>aAndB</code> list ot look like: <code>{1, 1, 2, 3, 4, 5}</code></p>