Seed for grid based game

Question

I'm trying to come up with a way to generate a grid/level from a seed.

I'm thinking of using a 6 x 6 grid with 3, possible tiles in each. The seed for that would be 108 characters long, i doubt anyone would want to copy 108 char long seed. (the game will probably be on iPhone, so the seed will be entered via keyboard) Anyways of shortening it?

I thought a fun way would be to use words. Separate the the grid into three 2 by 6 lines. and have each line represented by an english word. The player would then just type in 3 words which is a lot easier & gives a kind of name to the level.

Any thoughts on how i could achieve this?

(I'm currently using gamesalad)

Thank you for your time,

Jordan

Answer 1

Shorting the seed.

Well 108 characters is a little over kill. You have 6 by 6 cell so that's 36 cells total. Each cell has 3 different states yet a char has at min 64 different states (A-Z,a-z,0-9, and a few punctuations to keep it simple) So even with 36 character we have way more than we need.

So lets break it down some more. Computers work in binary. A bit is the smallest bit of information it can use. One bit can be on or off so it has 2 possible states. 2 bits can be off,off or off,on or on,off or on,on so that is 4 different states. If we add another bit we get two more states for every previous state so that is 4*2 = 8 states for 3 bits. Times by 2 again for a 4th bit we get 16 states, again for 32 and again for 64 which just happens to be the number of characters we want to use. So it takes 6 bits to store 64 possible states.

Now lets look at the grid. Each cell has 3 states each. So two cells have 9 possible combination 3*3 and for 3 cells its 3*3*3 = 27 next is 3*3*3*3 = 81 or 3 to the power of 4 cells or 3^4 = 81. We can use this trend to work out how many possible combinations there are for all 36 cells. 3 to the power of 36. That is a big number 150,094,635,296,999,121 or One hundred and fifty million billion combinations.

So how many bits do we need to store that number. I could cheat and ask the calculator but that's too easy,

Let's see, 3 cells have 27 combinations and 5 bits have 32. so 3 cells go into 36 cell 12 times and we have 5 bits for every 3 cells so 5*12 is 60bits. That's a nice round number as our chars are 6 bits each we can shove every possible grid combination into 10 char with some to spare. We have 5 spare combinations for every 3 cells so we have 60 combinations spare 12*5. Darn if only we had 4 more combinations that would be 64 which is 2^6 or 6 bits or one char. We can not take away half a character so 10 characters it has to be. BTW 4 combinations is two bits so take that from our 60 char bits and the minimum number of bits to store your grid is 58. 2 to the power of 58 should be just bigger than 3 to the power of 36.

Thus your grid requires 10 chars. Each being any one of ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789:) perfect (8 bytes 4 spare bits)

I pick my first 10 char seed BLINDMAN67 now what?