StoneWall (sigma2012) Demo Task at Codility.com Lesson 5 – Stacks and Queues – StoneWall (sigma2012) demo task solution code written in php. Gives 100/100 score at the time of publishing. By Alec | 26/02/2014 | Coding Tips & How-Toes, PHP, Programming & Freelancing, Programming Testing and Exams | Read more