两个ArrayLists之间的同步字符串

时间:2013-03-14 03:12:05

标签: java collections arraylist sorting

我有两个ArrayLists。

  • 第一个包含一组带有大写字母的单词 标点符号。

  • 另一个包含同一组词,但是带有 删除了大写和标点符号。

ArrayList1 ..... ArrayList2

MURDER! ........ murder

It's ........... its

Hello .......... hello

Yes-Man ........ yesman

ON ............. on

第二个数组包含按字母顺序排列的所有单词,并且每个单词中的所有字母都按字母顺序排列。它看起来像这样:

aemnsy
demrru
ehllo
ist
no

我想这样做,当我将ArrayList中的单词排列成字母顺序时,ArrayList中的所有单词都遵循套件:

ArrayList1 ..... ArrayList2

Yes-Man ........ aemnsy

MURDER! ........ demrru

Hello .......... ehllo

It's ........... ist

ON ............. no

我尝试用一​​两个for语句创建一个循环,但它最终没有工作并变得很长。我该怎么做呢?我该如何有效地做到这一点?

5 个答案:

答案 0 :(得分:5)

这是一个基于单个'键排序多个列表的功能。名单。列表不需要是相同的类型,此处的键列表是String类型,它用于对StringIntegerDouble进行排序列表(Ideone Example):

List<String> key = Arrays.asList("demrru", "ist", "ehllo", "aemnsy", "no");
List<String> list1 = Arrays.asList("MURDER!","It's", "Hello","Yes-Man", "ON");
List<Integer> list2 = Arrays.asList(2, 4, 3, 1, 5);            // Also use Integer type 
List<Double>  list3 = Arrays.asList(0.2, 0.4, 0.3, 0.1, 0.5);  // or Double type

// Sort all lists (excluding the key)
keySort(key, list1, list2, list3);

// Sort all lists (including the key)
keySort(key, key, list1, list2, list3);

输出

// Sorted by key:
[Yes-Man, MURDER!, Hello, It's, ON]
[aemnsy, demrru, ehllo, ist, no]
[1, 2, 3, 4, 5]
[0.1, 0.2, 0.3, 0.4, 0.5]

排序功能

可以找到Ideone示例here,其中包括参数验证和测试用例。

public static <T extends Comparable<T>> void keySort(
                                        final List<T> key, List<?>... lists){
    // Create a List of indices
    List<Integer> indices = new ArrayList<Integer>();
    for(int i = 0; i < key.size(); i++)
        indices.add(i);

    // Sort the indices list based on the key
    Collections.sort(indices, new Comparator<Integer>(){
        @Override public int compare(Integer i, Integer j) {
            return key.get(i).compareTo(key.get(j));
        }
    });

    // Create a mapping that allows sorting of the List by N swaps.
    Map<Integer,Integer> swapMap = new HashMap<Integer, Integer>(indices.size());

    // Only swaps can be used b/c we cannot create a new List of type <?>
    for(int i = 0; i < indices.size(); i++){
        int k = indices.get(i);
        while(swapMap.containsKey(k))
            k = swapMap.get(k);

        swapMap.put(i, k);
    }

    // for each list, swap elements to sort according to key list
    for(Map.Entry<Integer, Integer> e : swapMap.entrySet())
        for(List<?> list : lists)
            Collections.swap(list, e.getKey(), e.getValue());
}

答案 1 :(得分:4)

第一种方式 - 我使用的映射关键字来自arrayList2,值来自arrayList1。将数据放到地图取决于您。排序arrayList2后,我从map中获取它的值。

  List<String> arrList1 = new ArrayList<String>();

            arrList1.add("MURDER!");
            arrList1.add("It's");
            arrList1.add("Hello");
            arrList1.add("Yes-Man");
            arrList1.add("ON");

            List<String> arrList2 = new ArrayList<String>();
            arrList2.add("demrru");
            arrList2.add("aemnsy");
            arrList2.add("ist");
            arrList2.add("ehllo");
            arrList2.add("no"); 

            Map<String, String> map1 = new HashMap<String, String>();
            map1.put("aemnsy", "Yes-Man");
            map1.put("demrru", "MURDER!");
            map1.put("ehllo", "Hello");
            map1.put("ist", "It's");
            map1.put("no", "ON");

            Collections.sort(arrList2);

            for (String s : arrList2){
                System.out.println(s + "..........." + map1.get(s));
            }

第二种方式 - 另一种方法是只使用已经排序的TreeMap而不是两个ArrayList。

Map<String, String> map2 = new TreeMap<String, String>();
            map2.put("ehllo", "Hello");
            map2.put("aemnsy", "Yes-Man");
            map2.put("demrru", "MURDER!");
            map2.put("no", "ON");
            map2.put("ist", "It's");

            for (Map.Entry<String, String> entry : map2.entrySet())
            {
                System.out.println(entry.getKey() + "/" + entry.getValue());
            }

第三种方式 - 只使用2个ArrayList,但我们必须自己编写排序方法。您是否注意到您的2个ArrayList元素(如arrayList2中的aemnsy和arrayList1中的Yes-Man)具有相同的索引?我使用这一点。

  selectionSort1(arrList2, arrList1);

    for(int i = 0; i < arrList1.size(); i++){
        System.out.println(arrList2.get(i) + "---" + arrList1.get(i));
    }

   public static void selectionSort1(List<String> x, List<String> y) {
    for (int i=0; i<x.size()-1; i++) {
        for (int j=i+1; j<x.size(); j++) {
            if (x.get(i).compareTo(x.get(j)) > 0) {
                //... Exchange elements in first array
                String temp = x.get(i);
                x.set(i, x.get(j));
                x.set(j, temp);

                //... Exchange elements in second array
                temp = y.get(i);
                y.set(i, y.get(j));
                y.set(j, temp);
            }
        }
    }
}

答案 2 :(得分:0)

快速回答。

public class MapAlph {
    public static void main(String[] args) {
        HashMap<String, String> map = new HashMap<String, String>();
        String txt = "Murde!r!";
        ArrayList<Character> alph = new ArrayList<Character>();
        for (int i = 0; i < txt.length(); i++)
            if (Character.isLetter(txt.charAt(i)))
                alph.add(txt.charAt(i));

        Collections.sort(alph);
        Collections.reverse(alph);
        String val = "";
        for (Character c : alph)
            val += c;

        map.put(txt, val);
        System.out.print(txt + " ........ " + map.get(txt));
    }
}

答案 3 :(得分:0)

如果您愿意,可以使用TreeMap

Map<String, String> sortedMap = new TreeMap<String, String>();
sortedMap.put("demrru", "MURDER!");
sortedMap.put("ist", "It's");
sortedMap.put("aemnsy", "Yes-Man");
sortedMap.put("ehllo", "Hello");
sortedMap.put("no", "ON");

答案 4 :(得分:-1)

你可以试试这个:

import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;


public class SortService {

    public static void main(String[] args) {
        Map<String, String> originalMap = new HashMap<String, String>();
        originalMap.put("aemnsy", "Yes-Man");
        originalMap.put("demrru", "MURDER!");
        originalMap.put("ehllo", "Hello");
        originalMap.put("ist", "It's");
        originalMap.put("no", "ON");

        Map<String, String> sortedMap = new TreeMap<String, String>(originalMap);
        System.out.println(sortedMap);
    }

}

<强>输出:

{aemnsy=Yes-Man, demrru=MURDER!, ehllo=Hello, ist=It's, no=ON}