Algorithm to generate all letter combinations using recursion
<p>I remember this having a specific name, and there were example codes on various websites - but I can't remember what it was actually called so can't find anything...</p>

<p>Basically, I want to generate all the possible letter combinations in a loop. The output would be something like this:</p>

<pre><code>A
B
C
...
Z
AA
AB
AC
---
AZ
BA
BB
BC
</code></pre>

<p>etc...</p>
