检查泛型类型的对象是否在LinkedList中

Question

I have a LinkedList of generic type State . In this LinkedList I have hundreds or even thousands of State objects. How can I, in the most efficient way to check if newly generated State object is already in the list?

State object:

public State(PlayerAddress player, LinkedList<BoxAddress> boxList, char[][] map, String solution, String stateHash) {
    this.player = player;
    this.boxList = boxList;
    this.map = map;
    this.solution = solution;
    this.stateHash = stateHash;
    boxListString = boxListToString(boxList);
    mapString = mapString(map);
}
}

Additionally, State object consists of another generic objects as it is shown in the Constructor. How can I check if both State objects are the same in every aspect (PlayerAddress, LinkedList, etc.) ?

Answer 1

Have you tried the contains method? This could work. Also don't forget that you can overwrite stuff, so you could compare the hascodes as well by overwriting the hascode and compare methods.

Answer 2

In your case I would strongly suggest you will utilize the contains method. Which is the most efficient lookup for your case.

Looking at the java doc for contains:

public boolean contains(Object o) Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that (o==null ? e==null : o.equals(e)).

So you should only need to overwrite equals for your State class. The hashcode, will be required for sets.