CODEWITHSUNDEEP
javalinked-list
Bobby
Bobby

Reputation: 18305

How can I easily delete duplicates in a linked list in java?

How can I easily delete duplicates in a linked list in java?

Upvotes: 0

Views: 7569

Answers (6)

krezus
krezus

Reputation: 1451

you can use the distinct() method of Stream. The distinct() method works based on Stream and returns a stream that contains only a unique element. This method internally invokes the equals() method.

duplicateElements.stream().distinct().collect(Collectors.toList());

Upvotes: 0

mahesh
mahesh

Reputation: 11

import java.util.*;
import java.lang.*;

class Main
{
    public static void main (String[] args) throws java.lang.Exception
    {
        Collection<String> c = new LinkedList<String>();
        c.add("JAR");c.add("BDK");c.add("JDK");c.add("JAR");c.add("WAR");c.add("APK");c.add("BDK");
        c=new HashSet(c);
        c=new ArrayList(c);
        for(String s : c)
        {
            System.out.println(s);
        }
    }
}

Upvotes: 1

OtherDevOpsGene
OtherDevOpsGene

Reputation: 7471

Use a LinkedHashSet instead, and then you won't have duplicates in the first place.

Upvotes: 16

Michael Myers
Michael Myers

Reputation: 192015

Easily in terms of what? If it's a reasonably short list, the simplest solution is to dump it to a Set and then back to a List.

myList = new LinkedList<Whatever>(new HashSet<Whatever>(myList));

But why bother with this? If you don't want duplicates, you should be using a Set; if you only want a list so that you can keep the elements in the same order they were inserted, you can use a LinkedHashSet to get the best of both worlds: a Set that iterates predictably like a LinkedList.

Upvotes: 3

Welbog
Welbog

Reputation: 60436

Search through them and, if two represent the same thing, delete one of them.

What more do you want? Do you want advice on how to do this quickly? If that's the case, store the nodes in a hash table for easy matching when looking for duplicates.

Upvotes: 2

victor hugo
victor hugo

Reputation: 35848

I don't know if your requirements is to use a linked list but if not, use a Set instead of a List (you tagged the question as 'best-practices')

Upvotes: 9

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