My own homemade puzzle, I know it's solvable but I don't know the solution.
There are five men, each assigned a seat 1 to 5. Two are death row prisoners, one is a crazy guy, and two are innocent civilians.
You have been tasked with feeding these men each one of five dishes. Two dishes have poison and are for the prisoners, one dish has medication and is for the crazy man, The last two dishes are regular and are for the civilians, you don't know which dish is which.
The men know each other's identities but only know where the dishes intended for their roles are.
The prisoners always lie unless they have the civilians dish, in which case they tell the truth.
The crazy guy lies if he has the civilian's dish, tells the truth if he has the prisoner's dish and answers randomly if he has the correct dish.
The civilians always tell the truth unless they have the poisoned dish, in which case they lie.
You can ask them any of them questions that can be answered with a yes or no any number of times, and you can switch around the dishes in front of them as much as you'd like.
What strategy guarantees that, from any initial arrangement of people and dishes, you can give each person the correct dish with 100% certainty? How many yes/no questions and dish swaps does the strategy require?