qsort

This is a discussion on qsort within the C Programming forums, part of the General Programming Boards category; the program gets 6 random numbers. i've been trying to use the qsort function to print them in ascending order. ...

  1. #1
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    qsort

    the program gets 6 random numbers. i've been trying to use the qsort function to print them in ascending order.

    it seems to be printing the location in memory where they are stored rather than the numbers themselves..


    #include <stdio.h>
    #include <stdlib.h>
    #include <time.h> //for seeding randomiser

    #define MAX 6

    int rnd(int range);
    void seedrnd(void);

    int intcmp(const void *v1, const void *v2);

    int main()
    {
    int x;
    int results[MAX];
    seedrnd(); //prepare random-number gen.
    //display 6 random numbers
    printf("Here are your six National Lottery numbers:\n\n");
    while (x<6)
    {
    results[0]=rand();
    {
    results[0]++;
    }

    }


    qsort(results, MAX, sizeof(results[0]), intcmp);

    for (x=0;x<6;x++)
    printf("\nresults[%d]", &results[x]);

    system("PAUSE");
    return 0;
    }

    int rnd(int range)
    {
    int r;

    r=(rand()%range)+1; //random numbers
    return(r);
    }

    void seedrnd(void) //seed the random number
    {

    srand((unsigned)time(NULL));
    }

    int intcmp(const void *v1, const void *v2)
    {
    return(*(int *)v1- *(int *)v2);
    }

  2. #2
    and the hat of wrongness Salem's Avatar
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    > it seems to be printing the location in memory where they are stored rather than the numbers themselves..
    Because that's what you asked it to do

    >printf("\nresults[%d]", &results[x]);

    Try
    printf("\nresults[%d]", results[x]);

  3. #3
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    ok thanks i see that now...

    now i have the problem that the numbers generated are far too high..how can i edit the code so that the random numbers stay below 49?

  4. #4
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    Join Date
    Oct 2001
    Posts
    2,934
    Try this:
    Code:
    #include <stdio.h>
    #include <stdlib.h> 
    #include <time.h> //for seeding randomiser
    
    #define MAX 6 
    
    int rnd(int range); 
    void seedrnd(void); 
    
    int intcmp(const void *v1, const void *v2); 
    
    int main() 
    { 
    int x; 
    int results[MAX]; 
    seedrnd(); //prepare random-number gen. 
    //display 6 random numbers 
    printf("Here are your six National Lottery numbers:\n\n"); 
    for (x=0; x<6; x++)
    {
    //Generates number from 1 to 48
    results[x]=(rand() % 48) + 1;
    } 
    
    qsort(results, MAX, sizeof(results[0]), intcmp); 
    
    for (x=0;x<6;x++) 
    printf("results[%d]\n", results[x]);
    
    system("PAUSE");
    return 0; 
    } 
    
    int rnd(int range) 
    { 
    int r; 
    
    r=(rand()%range)+1; //random numbers 
    return(r); 
    } 
    
    void seedrnd(void) //seed the random number 
    {
    srand((unsigned)time(NULL)); 
    } 
    
    int intcmp(const void *v1, const void *v2) 
    { 
    return(*(int *)v1- *(int *)v2); 
    }

  5. #5
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    thanks, that worked perfect

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