Shapeways Software Engineer interview questions

The coding test contained a back-end problem, which had to be solved using Java or PHP and a front-end component which had to be solved with HTML, JavaScript and CSS.

Got a coding test which i solved with an efficient algorithm. Few days later got reject saying I doesn't match their requirements. Whereas my other friend got the interview and solved the exactly the opposite way it was asked to do and he got the call for next round.