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Join Date: May 2005

Posts: 42

Reputation: TimC is an unknown quantity at this point

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TimC

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Linked List

Nov 30th, 2005

Dear All.

I have a small problem with the code attached. I am trying to add an object to a linked list. When I try to compile I am getting an error. For the life of me I cant figure out the error. this is after 5hrs of head wrecking searching. Any help would be greatly appreciated. thx in advance Tim.

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christmas2.zip (3.9 KB, 8 views)

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Join Date: Apr 2005

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HyperEngineer HyperEngineer is offline

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Re: Linked List

Nov 30th, 2005

Tim,

I only time to look at one file. In Sequence.cpp I found this function. I believe this may cause a problem if the index is not valid.

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SeqItemType Sequence::retrieve(int index)
{
  if ((index < 1) || (index > size())){
    // can't delete something that isn't there
  }
  ListNode *cur = find(index);
  return cur->item;
}
SeqItemType Sequence::retrieve(int index)
{
  if ((index < 1) || (index > size())){
    // can't delete something that isn't there
  }
  ListNode *cur = find(index);
  return cur->item;
}

If the expression in the if statement is true it will still do the last bit of code, unless you wanted and if-else structure.
The find(index) will return zero if index is not valid. Then when it tries to resolve cur->item, that might give you a problem. Look at your code and see if you are ever returning 0 that will be used in a cur->item context. Check for 0. If it is, return or move on without doing anything.

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Join Date: Apr 2004

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Dave Sinkula Dave Sinkula is offline

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long time no c

Re: Linked List

Nov 30th, 2005

One would be the missing semicolon in "Sequence.h":

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typedef patient SeqItemType;

Others are things like returning a pointer from a function that is not declared as returning a pointer.

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