Getting max from LinkedList

Question

I'm making an application where the user can save travels with destination and length of travel. Then I somehow want to see what the longest are. All travels are objects in a LinkedList, and length of travel is integer.

How can I get the highest value of length of travel?

Solution: Ended up using iteration through nodes:

for (Travel travel : travelList) {
longest = travel.getLength();
destination = travel.getDest();
if (travel.getLength() >= longest)
{
    destination = travel.getDest();
}
}

I have tried Collections.max(MyTravelList), but without any luck. Got an error. I guess that it sort list in total, and not only by length. — janlindso, Apr 08 '13 at 16:54
http://docs.oracle.com/javase/6/docs/api/java/util/Collections.html#max(java.util.Collection) , also check Comparable, these are the tools you need... try yourself you should be able to get it. Also this previous post will be useful http://stackoverflow.com/questions/369383/best-way-for-get-min-and-max-value-from-a-list-of-comparables-in-java — AurA, Apr 08 '13 at 16:57

score 1 · Accepted Answer · answered Apr 08 '13 at 16:53

1

Consider iteration over each node of LinkedList to find out longest destination.

answered Apr 08 '13 at 16:53

Anton

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Actually, this will be working. Saving node in variable if highest. It seems this is easier to do than using a Comparator. But which is best, and why? – janlindso Apr 08 '13 at 17:02
There is no much difference, take a look at source code of Collection.max method. It does the same things and it requires N iteration. Probably, you can find max method more elegant. – Anton Apr 08 '13 at 17:11

AC1 · Answer 2 · 2013-04-08T17:02:59.600

0

If you are storing travels using your own java object, then here's the pointer. Look at Collections.max () and Comparator and Comparable interfaces.

edited Apr 08 '13 at 17:02

answered Apr 08 '13 at 16:55

AC1

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Bhesh Gurung · Answer 3 · 2013-04-08T17:04:21.980

0

You can utilize the public static <T> T max(Collection<? extends T> coll, Comparator<? super T> comp).

You need to create a Comparator for you object first, and supply an instance of the comparator while calling the method.

edited Apr 08 '13 at 17:04

answered Apr 08 '13 at 16:58

Bhesh Gurung

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score 0 · Answer 4 · answered Apr 08 '13 at 17:02

You may modify your Travel class so that it implements Comparable interface, and add something like.-

@Override
public int compareTo(Travel another) {
    return getLength().compareTo(another.getLength());
}

Then you can call

Collections.sort(travelsList);

to sort the list using your compare criteria defined in compareTo method

Getting max from LinkedList

4 Answers4