rand interval

This is a discussion on rand interval within the C++ Programming forums, part of the General Programming Boards category; looking for the easiest way to generate random numbers ranging from [-64 63] using rand(). can't seem to hack it....

  1. #1
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    rand interval

    looking for the easiest way to generate random numbers ranging from [-64 63] using rand().

    can't seem to hack it.

  2. #2
    CSharpener vart's Avatar
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    rand()%128 - 64
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  3. #3
    C++ Witch laserlight's Avatar
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    vart's solution works, but you might also want to read more: using rand()
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  4. #4
    and the hat of int overfl Salem's Avatar
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    Or "gasp, shock, horror", the FAQ
    http://faq.cprogramming.com/cgi-bin/...&id=1043284385
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  5. #5
    CSharpener vart's Avatar
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    vart's solution works
    It was provided because
    The first solution only works when N evenly divides into RAND_MAX
    N is 128 in this case and the condition should be fulfilled...
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  6. #6
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    You never answered my question from the last thread. There's a real possibility that you want unique numbers, and getting a random number in the range [-63, 64] is the wrong way to go about that.

  7. #7
    Code Goddess Prelude's Avatar
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    >N is 128 in this case and the condition should be fulfilled...
    Who said RAND_MAX has to be a power of two?
    My best code is written with the delete key.

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