Question

我在翻转LinkedList时遇到问题。换句话说，我需要它们以z-a顺序排序（与a-z相反）。我试过Collections.reverse但是没有生效？我有以下内容：

import java.io.*;
import java.util.*;
public class pa9Driver {
//create two list
//1st List is of type word class
//2nd list is of type Anagram_Family
public static List<Word> words = new LinkedList<Word>();
public static List<AnagramFamily> familyList = new LinkedList<AnagramFamily>();

//a main method for driver class
public static void main(String[] args) {
//call the generate method to read word from the file
generate_WordList();
//sort the word list
Collections.sort(words);
//generate the anagram family for the word
generate_FamilyList();
//sort the anagram family list      
Collections.sort(familyList, new anagramFamilyComparator());
//reverse the anagram family list
Collections.reverse(familyList);
topFive();
}//main ends

public static void topFive() {
int i;
for(i = 0; i < 15; i++) {
System.out.print(familyList.get(i).getCanonicalForm1() + ", ");
System.out.print(familyList.get(i).getSize() + ": ");
System.out.println(familyList.get(i));
   }
}

//method that read word
public static void generate_WordList() {
File inFile12=new File("words.txt");
Scanner fileRead1=null;
try {
fileRead1 = new Scanner(inFile12);
} catch (Exception exe) {
       exe.printStackTrace();
       System.exit(0);
   }

   //until the file has words read the words
   while(fileRead1.hasNext()) {
       words.add(new Word(fileRead1.next()));
   }
}
//generate the anagram and add it to the current family
public static void generate_FamilyList() {
Iterator<Word> readWord1 = words.iterator();
Word previousWord1 = words.get(0);
familyList.add(new AnagramFamily());
int index1 = 0;
while(readWord1.hasNext()) {
Word currentWord1 = readWord1.next();
if(currentWord1.getCanonicalForm1().equals(previousWord1
.getCanonicalForm1())) {
familyList.get(index1).add(currentWord1);
} else {
index1++;
familyList.add(new AnagramFamily());
familyList.get(index1).add(currentWord1);
  }
previousWord1 = currentWord1;
    }
  }
}

为了方便起见，我只会展示我拥有的前几行代码。目前：

[apers，apres，asper，pares，parse，pears，prase，presa，rapes，reaps，spare，spear]

[警告，改变，artels，estral，laster，ratels，salter，slater，staler，stelar，talers]

预期：

[矛，备用，收割，强奸，普雷萨，prase，梨，解析，削减，asper，apres，apers]

[taler，stelar，staler，slater，salter，ratels，laster，estral，artels，alters，alert]

Answer 1

尝试：

Collections.sort(familyList, Comparator.reverseOrder());

或者，您可以这样做：

Collections.sort(familyList, new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                return o2.compareTo(o1);
            }
        });

//Print list in reverse order
        for(String st : familyList){
            System.out.println(st);
        }

Answer 2

看到你的代码，似乎AnagramFamily是一种List，你没有排序。

您需要使用StringComparator对AnagramFamily（字符串列表）进行排序，以获得所需的输出。

难以按字母顺序颠倒链表

2 个答案: