Thread: Truly random characters (scrabble)

> Any suggestions?
ran = 'A' + rand() % 26;
printf("%c",ran);

See how those are equally distributed.

The problem you have is that towards the end of the loop, all that are left in your letters to choose from are the ones with a high count to start with. All the ones with counts of 1 or 2 have already been taken

Code:

void TileGenerate() {
    char ran; int i, j, k;

    srand((unsigned) time(NULL));

    /* put all the letters in the bag */
    k = 0;
    for ( i = 0 ; i < 27 && k < 100 ; i++ ) {
        for ( j = 0 ; j < count[i] && k < 100 ; j++ ) {
            RandA[k++] = alpha[i];
        }
    }

    /* now shuffle */
    for ( i = 0 ; i < 100 ; i++ ) {
        int p1 = rand() % 100;
        int p2 = rand() % 100;
        int temp = RandA[p1];
        RandA[p1] = RandA[p2];
        RandA[p2] = temp;
    }

    for (i=1; i<=100; i++) { //print random matrix
        if (i%10==0)
            printf("\n");
        ran = 'A' + rand() % 26;
        printf("%c ", RandA[i-1]);
    }
    return;
}

If you want it to really be like Scrabble, then you need to make an array storing a set number of each letter, and pull from it. Because Scrabble(TM) doesn't use random letters. It uses a fixed amount of each letter which are drawn randomly.

Quzah.

If you must end immediately, try the exit function. If you've shuffled the array, then it is in effect drawing them randomly. If you don't like doing that, then randomly jump to a spot in the array. If there's nothing there (meaning, you've set it to whatever you set it to when you've already used that letter), then roll foreward down the list until you run into a letter and use it. There are numerous ways to do it.

Quzah.

If you must end immediately, try the exit function. If you've shuffled the array, then it is in effect drawing them randomly. If you don't like doing that, then randomly jump to a spot in the array. If there's nothing there (meaning, you've set it to whatever you set it to when you've already used that letter), then roll foreward down the list until you run into a letter and use it. There are numerous ways to do it. You could also shrink the list as you pull from it.

Quzah.

Originally posted by Salem
> Any suggestions?
ran = 'A' + rand() % 26;
printf("%c",ran);
See how those are equally distributed.
[/code]

rand()%N does not give intergers uniformly/equally distributed over the set

Code:

{0,.....,N-1}

If RAND_MAX is large and N is small compared to RAND_MAX it will be a good approximation to an uniform distribution over the above set,(in my computer its value is only 32767) but if N is comparable to RAND_MAX then the deviation from uniformity is going to be significant.

But the tiles in the bag are already shuffled, so don't you just have a simple counter

int numTilesDrawn = 0;
char tile = RandA[numTilesDrawn++];

The only thing I see with the code is that you randomize both p1 and p2 at the same time. I don't know how well this works for you, I am making a card game and my shuffling routine basically just

increment through the array
creates a random index number between 0 and max_elements
then trades the current element with the random one.

You can increment through the array as many times as you want to make it more random.

Originally posted by vex_helix
The scrabble game can be against 2 - 4 people. So how do u shift from one person to another. I was thinking this:

Code:

while(true)
void GamePlay( which Player's turn?  and his tiles and his input) {
do the stuff
}

Have a variable called PlayerNumber. Whe the current player is finished, increment PayerNumber. When PalyerNumber == PlayerTotal, set it back to 0.

Now all your drawn characters can be put in an array with PlayerNumber as an index.

Originally posted by vex_helix
So another thing, in scrabble you can make up multiple words both vertically and horizontally. So suppose a person enters in a letter which makes two words. How will the computer know what words they are? Make it check both vertically and horizontally till it find a null space on the board?

Assume the letters are played across. As each letter is played check up & down for valid words