Thread: Lottery - C Programm

Hey folks, i've got a little problem with arrays. I progged this today but it won't work for me.. the debuger says it's an endless loop about the first "for" and "comparison" is the greatest number of integer right at the beginning.
May be you got an idea? Numbers shouldn't be doubled.
Thanks for helping..
and sorry for my bad english

Code:

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


#define number_lottery 6

int main(int argc, char** argv) {

    srand(time(NULL));
    int comparison = 0;
    int position = 0;
    int counter = 0;
    int check = 0;

    int lottery_output[number_lottery];

    for (position = 0; position <= number_lottery; position++) {
        do {
            int random = rand() % 49 + 1;

            for (counter = 0; counter <= position; counter++) {
                comparison = lottery_output[counter];
                if (random == comparison) {
                    check = 0;
                } else {
                    check = 1;
                    lottery_output[position] = random;
                }
            }
        } while (check == 0);
    }
    printf("%i ", lottery_output[0, 1, 2, 3, 4, 5]);
    printf("\n");

    return (EXIT_SUCCESS);
}

Thanks for answering my question.
Now I've got this:
It works partly but i will only recieve one lottery number six times.
An array mistake must be there.
I just wanted to keep you up to date but if there any suggestions i would take them lovely.

Code:

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


#define number_lottery 6

int main(int argc, char** argv) {

    srand(time(NULL));
    int comparison = 0;
    int position = 0;
    int counter = 0;
    int check = 0;
    int i;

    int lottery_output[number_lottery];

    for (position = 0; position < number_lottery; position++) {
        do {
            int random = rand() % 49 + 1;

            for (counter = 0; counter <= position; counter++) {
                comparison = lottery_output[counter];
                if (random == comparison) {
                    check = 0;
                } else {
                    check = 1;
                    lottery_output[position] = random;
                }
            }
        } while (check == 0);
    }
    
    /*  Output  */
    printf("The lottery numbers are: ");
 
    for(i=0; i < 6; i++)
    {
       printf("%i ", lottery_output[i]); 
    }
    printf("\n");

    return (EXIT_SUCCESS);
}

That's great but your logic is still very much flawed.

Here is what I'm assuming you're trying to do:
Create a list of random numbers between 1 and 49 (inclusive), with NO repeating numbers

Currently your code does not do that. You need to check the "check" variable, AFTER your for loop. Your if (random != comparison) needs to be inverted and then you check the check variable AFTER your loop. This will tell you if any of the elements up to the current element, is equal to the current element. If check variable hasn't changed after the inner for() loop, then you have a unique random number, if the check variable HAS changed, then you need to get a new random number (rand reset the check variable, which you don't do in the do while loop, like you need to).

Here is an example of what I'm talking about:

Code:

    for (position = 0; position < sizeof lottery_output/sizeof lottery_output[0]; position++) {
        int check; /* declare check variable */
        do {
            int random = rand() % 49 + 1;
            int comparison = 0;
            int counter = 0;
            check = 1; /* set check to success by default */

            for (counter = 0; counter < position; counter++) {
                comparison = lottery_output[counter];
                /* We found a variable that matches our current random number */
                if (random == comparison) { /* Inverted condition (was !=) */
                    check = 0; /* We failed to find a unique value, try again */
                    break; /* DONE no need to keep searching */
                }
            }

            /* We got a unique random number, assign it! */
            if (check)
                lottery_output[position] = random;

        } while (check == 0); /* Check is 1 so we exit the loop */
    }

EDIT: Also now that your check is defaulted to success, your loop condition can now have the PROPER condition of: count < position insttead of <= like you had previously which is wrong. The reason it was infinite looping with < was that your check variable was never getting set to 1 to exit the loop