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Thread: need help with code

  1. #1
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    Default need help with code

    for (int c=1; c<=6; c++)
    {
    int a=(int)(Math.random()*37+1);
    int b=(int)(Math.random()*8+1);
    System.out.print (a+" ");
    if (c==6) System.out.println ("- "+b);
    }

    I can't have the same number twice
    please help


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: need help with code

    I can't have the same number twice
    Then you need to save the previous numbers. When you get the next random number, check if you've saved it, if not save and return it, else get another number.

    How and where you save the the previous numbers depends on the range of the numbers. With a small range you could use a boolean[] array.

  3. #3
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    Default Re: need help with code

    I didn't really understand... can you put it in the code please?

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: need help with code

    Here's a simple example:
    Say there is a max of 20 values being generated: 0-19
    boolean[] savePastNbrs = new boolean[20];  // define an array to detect if a number has been used (init to false)
    start loop
    ...generate aNbr in range 0 to 19
    if(!savepastNbrs[aNbr]) {   // true if not saved yet
       savePastNbrs[aNbr] = true;  // remember this number used
       return aNbr;  // ok to use this one
    }
    end loop