Thread: Question?

  1. #1
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    Question?

    I am transfering from a jounior college to a four year college. This semester I am taking science classes (no programming classes). I have talked to other students in the computer science program and most of them are clueless about pointers. I have taken up to the first data structures at the jounior college I was attending. Is it possible to do a linked list or a Queue without pointers? The students at the four year college I have started going to are focused on pass by reference.

  2. #2
    Guest Sebastiani's Avatar
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    No there is not and why should there? Pointers aren't THAT difficult...
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  3. #3
    Code Goddess Prelude's Avatar
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    I honestly do not see the problem everyone has with pointers. A pointer is simply a variable that holds an address. Everyone gets so caught up in implementation that they forget that basic fact and become confused.

    -Prelude
    My best code is written with the delete key.

  4. #4
    ....
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    I think that many people get confused because they think too abstract. As Prelude says, a pointer is just a variable. The only difference with 'usual' variables is that it contains an address. Perhaps programming books should tell something about how memory in a computer is organised, like K&R does. Then people would better understand what a pointer is.

  5. #5
    Mayor of Awesometown Govtcheez's Avatar
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    I know that when I was learning about them, the main problem wasn't understanding what they are (since every tut under the sun says "it's a variable that contains an address"), but how to use them. When to dereference them, and the like. Also, I think scop should be taught before this - when I was beginning to learn, I couldn't figure out why you'd ever want to use them, because I didn't totally get that variables declared in a function couldn't be altered in another one without the use of them.

  6. #6
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    You can do a Queue without pointers. But a linked list would be difficult.

  7. #7
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    For a linked list without pointers, you'll have to create 2 arrays:

    int data[100],next[100];

    data[] will contain the actual data values, and corresponding next[] will contain the next element after the current one.

    e.g.

    index data next
    0 20 2
    1 25 -1 < --- can use this to indicate end of list
    2 56 4
    3 99 1
    4 23 3


    So the linked list goes like this: 0 -- 2 -- 4 -- 3 -- 1 -- END

    There are many modifications/additions possible to this of course.

    Hope this helps

  8. #8
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    Just adding...

    You can also have a prev[] array to hold index of previous element in case you want a doubly linked list.


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