I did this day under the direction of a friend who was learning programming: we walked through the problem together, with me asking what to do next, helping him refine his ideas and then translating them to code. For this reason, I chose a not-too-hard language, even though the problem is not too hard either (I thought of writing it in a Makefile, but that would not have been beginner-friendly :D ).

To run it, put your code in input.txt then run php solution.php.

Problem: Space Stoichiometry