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‫So now we're going to write our function for delete node.

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‫And what we're going to do here is we're going to delete a node at a particular index.

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‫So I'm going to bring up a linked list.

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‫And just like with Insert, we can't have an index out of range.

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‫So on this end we would say an index less than zero.

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‫And on this end we would say an index greater than or equal to the length.

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‫So we'll put both of these in an if statement.

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‫If index is less than zero or index is greater than or equal to the length, we're just going to run

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‫return because there's not a node there to delete and this will break us out of the function.

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‫Now, before I move past this, I'm going to bring this code back in and compare this to insert because

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‫an insert we also had an if statement to check to see if something was out of range.

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‫With delete node we run return and with insert we returned false.

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‫So why the difference?

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‫And the difference is the return type delete node returns void and insert returns a boolean.

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‫So I'm going to bring the linked list back up and we have already written code for removing the first

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‫item in the linked list.

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‫So we'll say if the index is equal to zero will return delete first.

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‫And once again, I'm going to bring this code back in and compare this to insert because this is a bigger

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‫difference between delete node and insert.

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‫So up here we returned delete first, but down here we don't return pretend.

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‫And the reason for that is that delete first and delete node have the same return type which is void.

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‫But down here pre pen has a return type of void and insert has a return type of boolean so those don't

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‫match.

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‫So because of this you can't run return.

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‫Pretend you can only do that when the return types match.

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‫So an insert we have to run prepared and have a second line for the return statement.

27
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‫So now let's bring back the linked list and look at removing the last item.

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‫And the length list will say if the index is equal to the length minus one return delete last.

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‫So now let's put this back and look at removing an item somewhere in the middle.

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‫We'll do that at the index of two.

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‫So we'll have a variable temp that we'll use to delete the node, but we're also going to need a variable

32
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‫to point at this node.

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‫And the reason why is if we remove this node, we need to have a way of getting the three arrow over

34
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‫to the seven and that arrow will be previous next.

35
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‫So let's bring this back and create.

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‫These two variables will set previous to be equal to get at index minus one and for the temp variable

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‫we could run get again.

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‫But that's not the most efficient way to do it because get is O of NW.

39
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‫So we're going to do it like this where we set temp to be equal to previous next and that is o of one.

40
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‫So now let's put this in with the rest of our code and now we'll bring back the linked list.

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‫So I'm going to put that node up here.

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‫So the first thing we're going to do is set previous next to be equal to temp next.

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‫We'll do that with this line of code, previous next equals tip next, and that moves that arrow down

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‫there.

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‫So now that we've done that, we'll run delete temp and that will delete this node.

46
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‫And the only thing left to do is to decrement the length.

47
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‫So now let's put this in with the rest of our code, and that is the entire delete node function.

48
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‫We'll look at this code in a moment and VS code.

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‫And when we do, we'll create this linked list one through five.

50
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‫So first we'll check to make sure this works when deleting a node somewhere in the middle, and then

51
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‫we'll print out the linked list and then we'll remove the first item, print out the link list again,

52
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‫and then finally remove the last item and print out the link list one more time.

53
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‫So now let's flip over and take a look at this.

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‫So there is our delete node member function there added to our linked list class and I'll scroll up

55
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‫and in our main function that creates that linked list one through five and we'll start out here by

56
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‫printing out that linked list with all five items in it.

57
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‫And I'll scroll up again and with this code we'll run delete node three different times, once in the

58
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‫middle, once on the first node and once on the last node.

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‫So I'll run this.

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‫And I'll move this over a little bit.

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00:05:28,130 --> 00:05:31,850
‫And you can see up here, this is our entire length list, one through five.

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‫This is after we deleted a node in the middle.

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00:05:34,520 --> 00:05:39,950
‫This is after we deleted the first node and this is after we deleted the last node.

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‫So it looks like we have a working member function for delete node.