rand() trouble

This is a discussion on rand() trouble within the C++ Programming forums, part of the General Programming Boards category; I'm having a bit of trouble using the random function rand(). It does kinda generate random numbers but its always ...

  1. #1
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    rand() trouble

    I'm having a bit of trouble using the random function rand(). It does kinda generate random numbers but its always the same numbers in the same order when the program starts. I read about this somewhere before but i couldnt get anything from searching the forum. The header i am using is just iostream.

    Heres where I am using the function:

    Code:
    y = (rand() % difficulty);
    I want a random number between 1 and whatever difficulty is set to (which I have been setting it to 10 when I have been using it).

    Please help!

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    Quote Originally Posted by -Dan-
    I'm having a bit of trouble using the random function rand(). It does kinda generate random numbers but its always the same numbers in the same order when the program starts. I read about this somewhere before but i couldnt get anything from searching the forum. The header i am using is just iostream.

    Heres where I am using the function:

    Code:
    y = (rand() % difficulty);
    I want a random number between 1 and whatever difficulty is set to (which I have been setting it to 10 when I have been using it).

    Please help!
    You need to use the srand() function to seed the random number generator. The most common way to do this is:

    Code:
    srand((unsigned int)time(NULL));
    rand() is not a true random number generator, so if you don't seed it you certainly won't get a different sequence every time.

  3. #3
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    When all else fails, read the instructions.
    If you're posting code, use code tags: [code] /* insert code here */ [/code]

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    Aaaah cheers!

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