Lotto problem

Long back there was one question related to Lotto

http://cboard.cprogramming.com/showt...threadid=35508

Here is my code for that, can anybody optmize it further,

Code:

---

main()
{
        int i,k,j = 6;
        int a[6];

        while ( getch() == 'C')
        {
                j = 6;
                while (j)
                {
                        k = 6-j;
                        i = (rand())%47;
                        a[k] = i;

                        while ( k-- )
                        {
                                if ( a[k] == i )
                                {
                                        k = 6-j;
                                        i = (rand())% 47;
                                        a[k] = i;
                                }
                        }
                        printf(" i = %d\t",i);
                        j--;
                }
                printf("\n");
        }
}

---

Well, I'm bored, so here's my attempt:

Code:

---

#include <stdio.h>
#include <stdlib.h>

#define GONE -1
#define ASIZE(a) (sizeof((a)) / sizeof((a)[0]))
#define YUMYUM while (getchar() != '\n')

int main(void)
{
  int numbers[50];
  int i, k;
 
  srand(time(NULL));
   
  for (i = 0; i < ASIZE(numbers); i++)
    numbers[i] = i + 1;

  printf ("Generate Numbers (y/n): ");
  while (getchar() == 'y')
  {
    YUMYUM;
    for (i = 6; i ; i--)
    {
      for (k = GONE; k == GONE; k = numbers[rand() % ASIZE(numbers)]);
      printf ("%d ", k); 
      numbers[k-1] = GONE;
    }
    printf ("\nGenerate Numbers (y/n): ");
  }
 
  return 0;
}

---

But it can only generate eight batches of six numbers before it goes a tad wrong ;)

At 9th iteration, code display only two numbers and stops.

Let me check why is this happening..

>>Let me check why is this happening..
You've got 5 minutes to find the bug.... come on... clock's ticking... :D (In case you didn't realise, I know what it is... it's a design fault ;)

Array size

Don't you think that as a limitation?

>>Array size
The size of the array does affect it, but it doesn't matter how big the array is, it will always stop at some point, because ........

>>Don't you think that as a limitation?
Yeah, I suppose so, either term is fine. It just depends if you're the user or the programmer. A user would say it's broken, and a programmer would say its a limitation/design issue.

Check this $$$$ out: :D

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>


signed short int numbers[47] =
{
        0, 1, 2, 3, 4, 5, 6, 7,
        8, 9,10,11,12,13,14,15,
        16,17,18,19,20,21,22,23,
        24,25,26,27,28,29,30,31,
        32,33,34,35,36,37,38,39,
        40,41,42,43,44,45,46
};

signed short int getnumber( void )
{
        static signed short int high = 47;
        signed short int current = rand( ) % high--;
        signed short int temp = numbers[current];
        numbers[current] = numbers[high];
        numbers[high] = -1;

#ifdef DEBUG
        {
                /* If you're confused as to what's happening, enable debug.*/

                int x;
                for( x = 0; x < 47; x++ )
                        printf("%d%c", numbers[x], x%10==9?'\n':' ' );
                getchar( );
        }
#endif
       
        return temp;
}

int main( void )
{
        signed short int winningnumbers[6] = { -1,-1,-1,-1,-1,-1 };

        srand( time( 0 ) );

        winningnumbers[0] = getnumber( );
        winningnumbers[1] = getnumber( );
        winningnumbers[2] = getnumber( );
        winningnumbers[3] = getnumber( );
        winningnumbers[4] = getnumber( );
        winningnumbers[5] = getnumber( );

        printf("Tonight's winning numbers are...\n");
        printf("%d %d %d %d %d %d\n",
                winningnumbers[0], winningnumbers[1],
                winningnumbers[2], winningnumbers[3],
                winningnumbers[4], winningnumbers[5] );

        return 0;
}

---

*Cackles like a demon!*

Please don't use this for homework.
[edit]
The only way to (probably) optimize this further would be to bypass the function call and repeat that code inline.
[/edit]

Quzah.

What, no incredibly confusing #define's Quzah? :D Neat solution though...

Since the original does not call srand, and for me it generates the sequence {25,39,35,33,19,34}, how about this?

Code:

---

#include <stdio.h>
int main(void)
{
  int lotto[] = {25,39,35,33,19,34,0}, *number = lotto;
  while(*number)
      printf("%2d ", *number++);
  return 0;
}

---

But assuming we want different numbers to be picked, I might try this.

Code:

---

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int main(void)
{
  int lotto[6],i,j;
  srand(time(NULL));
  for(j = 5; j >= 0; --j)
  {
      REDO:
      lotto[j] = rand() % 46 + 1; /* 1-46 */
      for(i = 5; i > j; --i)
      {
        if(lotto[i] == lotto[j])
        {
            goto REDO;
        }
      }
      printf("%2d ", lotto[j]);
  }
  putchar('\n');
  return 0;
}

---

Quote:

---

goto REDO;

---

:D That's just horrible. The idea was to optimize, not obfuscate. Still, it's always to see interesting to see other implementations.

Quzah.

Quote:

---

Originally posted by quzah

Code:

---

goto REDO;

---

:D That's just horrible.

---

Thank you.

For my next trick I will use void main(void) in a completely 100% standard implementation!
[Of course, it would be in a freestanding environment.]