Question 64
Wonderland has $n$ cities. Each pair is connected by one directed road, from one city to the other. Alice asks the King of Hearts questions: each time she chooses a pair, and he identifies the starting city of their road.
Prove that with at most $5 n$ questions, Alice can determine whether a city has at most one outgoing road.
Prove that with at most $5 n$ questions, Alice can determine whether a city has at most one outgoing road.