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up vote 1 down vote favorite

I have an ArrayList of Strings with duplicate elements. Every 3 rows make an entity:

2
550111.55
1, 3

3
550111.55
1, 2, 3

2
155.55
1, 2

3
550111.55
2, 3, 1

2
155.55
2, 1

2
550111.55
3, 1

3
550111.55
3, 1, 2

All the elements are Strings. The first number says the number of participants, the second says the value, and the third which elements make it up. So I have duplicates like 

3
550111.55
3, 1, 2

and

3
550111.55
1, 2, 3

and 

3
550111.55
2, 3, 1

The number of elements says the number of duplicates, so I must remove all the duplicates, in this case, delete all but one instance, for example:

3
550111.55
2, 3, 1

I am trying to do it like this :

ArrayList<String> lista_rezultata1=new ArrayList<String>();
lista_rezultata1=lista_rezultata;
//set to count to 3 in arraylist since data I need to split and evaluate are always on the third place
int number1=0;
int number2=0;
String[] part1=null;
String[] part2=null;
int removefromlist=0;
for (int i = 0; i < lista_rezultata.size(); i++) {
    if(number1==3)number1=0;
    if(number1==2)//If it is a third element it is the one with "," that I split
    {
        part1=lista_rezultata.get(i).toString().split(",");
    }

    for (int j = 0; j < lista_rezultata1.size(); j++) {
        if(number2==3)number2=0; 

        if(number2==2 && i!=j && number1==2)//If it is a third element it is the one with "," that I split, first must already be splited
        {
            part2=lista_rezultata1.get(j).toString().split(",");

            for (int k = 0; k < part1.length; k++) {
                for (int l = 0; l < part2.length; l++) {
                    if(part1.length==part2.length)   //if they have the same number of elements
                    { 
                        if(part2[l].equals(part1[j]))
                        {
                            .....some code
                        }
                    }
                }
            }
        }

        number2=number2+1;   
    }
    number1=number1+1; 
}

So I am hoping there is a better way ...

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3 Answers

up vote 3 down vote accepted

Your approach is all wrong I'm afraid...

  • Create a class to represent your items
  • Override the equals() method that returns true if your item values are the same
  • Override the hashCode() method to produce an int value based on the same values you compared in your equals() method (so hashCode "agrees with" equals)
  • Use a Set<Item> to save your items - sets use equals() to ensure there are no duplicates

You may wish to use a LinkedHashSet for you Set implementation:

Set<Item> set = new LinkedHashSet<Item>();

A LinkedHashSet will ensure the iteration order of its elements in the same order they were inserted.

share|improve this answer
    
You are right about the classes but what am I to do with Strings that go like 1,2,3 and 2,3,1 how am I to present these and do not mess up the order in which they go... –  Jovo Krneta May 22 '13 at 0:54
    
Use a LinkedHashSet, which iterate in inserted order –  Bohemian♦ May 22 '13 at 2:16
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up vote 0 down vote

If the elements parts had their members in order, then you would have actual duplicates, which should simplify things.

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It is importand that they are kept in the same order if I have 1,2,3 then 2,3,1 and 3,1,2 it is important that I am left with at lest one combination and they must be within same entity - the group of 3 , first is the number of participants , second is the value and the third are the ones that make the circle , these are in a fact results from graph database ... –  Jovo Krneta May 22 '13 at 0:45
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up vote 0 down vote

You you should probably use ArrayLists instead. However even if you prefer not to, you can check if an array contains a certain element like this:

Arrays.asList(yourArray).contains(element);
share|improve this answer
    
I am splitting the String 1,2,3 it may be that there is a combination like 1,2,3,4 and it is not the same ...It does contain it , all the elements but it is not for removing.. –  Jovo Krneta May 22 '13 at 0:52
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