Thread: Print Randomly!

  1. 12-09-2008 #1
    davewang
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    Print Randomly!

    Hi everyone! i got an idea, but not sure it is possible to make it in C or not. Here the thing:
    I want to create a program for testing vocabulary. I think that i can just simply apply the printf function to print out the word and then print out the definition, but the thing is I don't want to run the program everytime just with the same print order. I want it to print randomly everytime I run the program (for effective testing vocabulary). So, I just wonder if there is anyway to create something like that. If so, can you tell me what function i have to use? so i can know how to start it. Hopefully yes!
  2. 12-09-2008 #2
    matsp
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    You can use rand() to get a random number in the range 0..RAND_MAX - you can obviously change the range of this, for example using the % operator.

    To ensure that you start in a different place, you may want to use a call to srand(), with for example "current time" as the input.

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.
  3. 12-09-2008 #3
    davewang
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    thank you! i found it very useful, and one more question, is it possible to prevent the same random number printing out? because if the same random number pop up , i'm sure that some vocabularies won't show up! this will turn out really bad...
  4. 12-09-2008 #4
    matsp
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    What you can do, instead of taking a random number each time, shuffle [1] the words listed in the dictionary - just like you would deal out a deck of cards - you don't pull cards from anywhere in the deck, you shuffle the cards in the deck, and deal out in the order they "landed".

    Try googling for "shuffle algorithm".

    [1] Shuffle is the complete opposite of a sort.

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.
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