Question

public Link insert(String data, int where)
{
    Link temp = first;
    //If list is empty, insert as first
    if (first == null)
    {
        first = new Link(data, where);
        return first;
    }
    //List is not empty
    else
    {
        while (temp != null)
        {
            //If data is less than first, then insert as first
            if (data.compareTo(temp.getdData()) < 0 && temp == first)
            {
                Link newLink = new Link(data, where);
                newLink.setNext(first);
                first.setPrevious(newLink);
                first = newLink;
                return newLink;
            }
            //If data is less than current, then insert before current
            else if (data.compareTo(temp.getdData()) < 0)
            {
                Link newLink = new Link(data, where);
                newLink.setNext(temp);
                newLink.setPrevious(temp.getPrevious());
                temp.getPrevious().setNext(newLink);
                temp.setPrevious(newLink);
                return newLink;
            }
            //If data is more, but your at the end of the list.
            else if (data.compareTo(temp.getdData()) > 0 && temp.getNext() == null)
            {
                Link newLink = new Link(data, where);
                temp.setNext(newLink);
                newLink.setPrevious(temp);
                newLink.setNext(null);
                last = newLink;
                return newLink;
            }
            //Else keep going forward
            else
                temp = temp.next;
        }
    }
    return temp;
}

我可以插入列表中，但出于某种原因，它不会按顺序插入。例如，如果链接的数据是＆＃34; Hello＆＃34;我想在＆＃34; aaa＆＃34;中插入一个链接，它不会在＆＃34; Hello＆＃34;之前插入新链接。链接。

Answer 1

看看java比较字符串的方式：

java> "aaa".compareTo("Hello")    // positive number
java> "Aaa".compareTo("Hello")    // negative number

原因是字符'a'的ASCII码大于'H'。

顺便说一句，你最好在你的代码中使用.equals（）而不是==来比较Java中的String，看一下这个链接： http://perso.ensta-paristech.fr/~diam/java/online/notes-java/data/expressions/22compareobjects.html

Answer 2

如果你重新实现集合 - 那就是你做错了什么的红旗。

您的任务可以更简单地解决：

public class Link {
    private final String data;
    private final int where;
    ...
}

public class LinkComparator implements Comparator<Link> {
    @Override
    public int compare(Link o1, Link o2) {
        return o1.data.compareToIgnoreCase(o2.data);
    }
}

public static void main(String[] args) {
    NavigableSet<Link> links = new TreeSet<Link>(new LinkComparator());

    links.add(new Link(...));
}

无法使用Java插入双向链接，双端列表

2 个答案: