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Thread: How to modify System.arraycopy ?

  1. #1
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    Default How to modify System.arraycopy ?

    public static native void arraycopy(Object src, int src_position,  
                                            Object dst, int dst_position,  
                                            int length);


    My object contain two parameters (int x, char y)

    i want to increment all "x" elements each time i copy my array .

    actually i copy with O(n) and next i increment with also O(n) this decrease the performance !!!

    if we can modifiy arraycopy to copy and increment element by element the complexity will be O(n).


  2. #2
    Administrator copeg's Avatar
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    Default Re: How to modify System.arraycopy ?

    The complexity however you do it is O(n) - you've got to loop over the array somehow.

    if we can modifiy arraycopy to copy and increment element by element
    Systems.arraycopy is native

  3. #3
    Senile Half-Wit Freaky Chris's Avatar
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    Default Re: How to modify System.arraycopy ?

    Just to back up copeg's points about the O(n),

    If you look at the way you listed it, it was going to be O(2n), in Big-O notation we are not interested in that 2 as it is insignificant. Thus as copeg pointed out it will still be O(n)! He is quite right saying that it will also be O(n) best case.

    Chris
    chris[at]javaprogrammingforums[dot]com

    Prifysgol Bangor University, North Wales

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