An old friend of mine asked me to help his daughter work out a project. I worked it out rather simply with switches, but that's not what he wants.
Here's the deal. His daughter has a skull that has thirteen different areas. She wants to have thirteen different sheets on the table with a "contact" (thumbtack) on each sheet and a "contact" (thumbtack) on each of the thirteen areas of the skull that correspond to those sheets.
She wants to take a probe from the thumbtack on a sheet and touch it to the contact on the skull. If the person touching the probe from the sheet to the correct contact on the skull, it lights a green light. If they touch it to the wrong contact on the skull it lights a red light.
Given a lot of digital logic or a microprocessor, I can do it easily. Given a boatload of diodes, I can do it easily. I can't do it trivially.
Am I missing something or is this not a trivial problem?