In a standard game of battleships, what is the minimum number of strikes you will need to make to guarantee hitting at least one boat?

Battleships is played on a 10x10 Grid,
You are allowed:-
1 Battle Ship (4x1)
2 Cruisers (3x1)
3 Destroyers (2x1) and
3 Submarines (1x1)

NOTE:-These rules are slightly different than those of the board game, I am using these so that all members can give the same answer.

Using my technique, I guessed at every fourth cell. This makes sure that you hit the Battleship, no matter where it is located. Depending on how you start, you can end up with as few as 24 moves before you must hit a ship. 1's represent my guesses in the arrangement below. As you can see, there is no row or column with 4 zeroes in a row. I know it isn't great, but it was worth a try.

0010001000
0001000100
1000100010
0100010001
0010001000
0001000100
1000100010
0100010001
0010001000
0001000100

Posted by Justin on 2005-07-24 03:46:37