Just two small things that in case the number was very big could be helpful.

Update LevenshteinDistance.java

Fix link & added link: readme.md

* fix some bugs
* delete duplicate files
* format code

Efficiency

Debug HexaDecimalToDecimal.java

Documentations added

Update GenericArrayListQueue.java

Fix #771(position=size causes NullPointerException)

…uses NPE"

This reverts commit 7eb0785.

Fix #773 (Deleting an element that doesn't exist causes NPE)