On Android the free app "Simon Tatham's Puzzles" has an implementation of Mastermind and this is the same algorithm I use to solve it. It's not foolproof (it c

On Android the free app "Simon Tatham's Puzzles" has an implementation of Mastermind and this is the same algorithm I use to solve it. It's not foolproof (it can get tricky if you're unlucky finding the location of pegs) but it's a very easy algorithm to remember and implement.