Is there a way to add unique items to an array without doing a ton of comparisons?

Posted by hydroparadise on Programmers See other posts from Programmers or by hydroparadise
Published on 2012-11-01T15:02:09Z Indexed on 2012/11/01 17:15 UTC
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Filed under:

algorithms

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array

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loops

Please bare with me, I want this to be as language agnostic as possible becuase of the languages I am working with (One of which is a language called PowerOn). However, most languanges support for loops and arrays.

Say I have the following list in an aray:

0x  0  Foo
1x  1  Bar
2x  0  Widget
3x  1  Whatsit
4x  0  Foo
5x  1  Bar

Anything with a 1 should be uniqely added to another array with the following result:

0x  1  Bar
1x  1  Whatsit

Keep in mind this is a very elementry example. In reality, I am dealing with 10's of thousands of elements on the old list. Here is what I have so far.

Pseudo Code:

For each element in oldlist
 For each element in newlist
  Compare
  If values oldlist.element equals newlist.element, break new list loop
  If reached end of newlist with with nothing equal from oldlist, add value from old list to new list
 End
End

Is there a better way of doing this? Algorithmicly, is there any room for improvement? And as a bonus qeustion, what is the O notation for this type of algorithm (if there is one)?

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