multiply link list

This is a discussion on multiply link list within the C Programming forums, part of the General Programming Boards category; can anybody tell me how to multiply two linked lists?? i want to multiply large nos., consisting of hundreds of ...

  1. #1
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    Unhappy multiply link list

    can anybody tell me how to multiply two linked lists??

    i want to multiply large nos., consisting of hundreds of digit.
    i have stored the nos in link list form as one digit per node.
    now how to perform the multiplication???

    or

    is there any other way to multiply large nos???

  2. #2
    and the hat of int overfl Salem's Avatar
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    Well do you know how to multiply on paper?

    Eg.

    12
    34

    Multiply these two digits first, they'll be the ones at the end of your two linked lists.
    The result you store at the end of a third linked list.

    Rinse and repeat, according to the rules of multiplication.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
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  3. #3
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    ya i understand but its highly complicated to implement!!!

  4. #4
    and the hat of int overfl Salem's Avatar
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    How so?

    You have a couple of doubly linked lists, and you work your way all to the end of one, for each step of the other.

    Try it with fixed length arrays first if you're unsure of the algorithm.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  5. #5
    Algorithm Dissector iMalc's Avatar
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    If you're just as willing to use C++ instead of C then I've already written an efficient variable-sized large integer class. "varbigint" on my useful classes page of the below site.
    My homepage
    Advice: Take only as directed - If symptoms persist, please see your debugger

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  6. #6
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    Quote Originally Posted by mradul.exe View Post
    ya i understand but its highly complicated to implement!!!
    Write down how to do it. Given a list of digits An through A0, and Bm through B0, how do I get the product of A and B?
    It is too clear and so it is hard to see.
    A dunce once searched for fire with a lighted lantern.
    Had he known what fire was,
    He could have cooked his rice much sooner.

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