Generating random number from set

This is a discussion on Generating random number from set within the C Programming forums, part of the General Programming Boards category; The problem asks me to write a c statement that will assign an int variable a random number from [25, ...

  1. #1
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    Generating random number from set

    The problem asks me to write a c statement that will assign an int variable a random number from [25, 50, 75, 100]

    I am thinking of using rand() but I'm not sure how

    perhaps?
    for (int i = 0; i <=100;i*2)
    int random_number=rand(i);

    I'm not even sure that's allowed
    Last edited by Hybodus; 12-20-2010 at 09:51 AM.

  2. #2
    Gawking at stupidity
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    I would put your set in an array:
    Code:
     int set[] = { 25, 50, 75, 100 };
    Then you can use your rand() result as an index into set:
    Code:
     int random_number = set[<random number between 0 and 3 inclusive>];
    If you understand what you're doing, you're not learning anything.

  3. #3
    C++ Witch laserlight's Avatar
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    itsme86's suggestion is a more general solution, but in this case you can map the integers in the range [0, 3] to those numbers by a simple formula, e.g., ((rand() % 4 + 1) * 25).
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