用Java克隆Iterator？ [英] Clone an Iterator in Java?

问题描述

在游戏中我有一个玩家列表，让我们这样说：

In a game I have a list of players, let's say like this:

LinkedList<String> players = new LinkedList<String>();

我想让每个玩家与其他玩家互动，所以我写了两个嵌套循环：

I want to let each player interact with each of the other players, so I write two nested loops:

Iterator<String> i1 = players.iterator();
while (i1.hasNext()) {
    String p1 = i1.next();
    Iterator<String> i2 = players.iterator();
    // But I want to do this: Iterator<String> i2 = i1.clone();
    while (i2.hasNext()) {
        String p2 = i2.next();
        System.out.println("Interact: " + p1 + ", " + p2);
    }
}

因为我只希望每对玩家互动一次，我想在外环的当前玩家之后用玩家开始内循环。所以我想克隆迭代器，但是不能编译。

Since I only want each pair of players to interact once, I want to start the inner loop with the player after the outer loop's current player. So I want to clone the iterator, but that doesn't compile.

那么，我该怎么做呢？

推荐答案

以下将执行此操作：

ListIterator<String> i1 = players.listIterator(0);
while (i1.hasNext()) {
    String p1 = i1.next();
    ListIterator<String> i2 = players.listIterator(i1.nextIndex());
    while (i2.hasNext()) {
        String p2 = i2.next();
        System.out.println("Interact: " + p1 + ", " + p2);
    }
}

它依赖于 ListIterator 能够从给定位置开始并知道其当前位置。

It relies on the ListIterator's ability to start from the given position and to also know its current position.

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