Suppose you want to crack a code composed of 4 digits (each between 0 to 5 when repetitions allowed) and you get feedback like in mastermind, how can you find it in less than 5 guesses in an effective way (except Knut's way which is forbidden)?
Which way did you find?
My way: First, I though creating an array with all possibilities. I wanted to begin with guess $0101$. then i'd go over my array and remove all possiblities which doesn't fit and then sending the first fitting option to the "feedback giver". Problem is I'm not sure it converges in 5 movements or less.