Syncronized sorting between two ArrayLists

arraylist, collections, java, sorting

Solution

Here is a function to sort multiple lists based on a single 'key' list. The lists do not need to be the same type, here the key list is type `String` and it's used to sort a `String`, `Integer`, and `Double` list (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);

Output:

// 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]

Sort Function

An Ideone Example can be found here which includes validation of parameters and a test case.

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());
}

Problem

I have two ArrayLists. The first contains a group of words with capitalization and punctuation. The other contains this same group of words, but with the capitalization and punctuation removed. . ``` ArrayList1 ..... ArrayList2 MURDER! ........ murder It's ........... its Hello .......... hello Yes-Man ........ yesman ON ............. on ``` The second array has all the words alphabetized and all the letters in each word alphabetized. It looks something like this: ``` aemnsy demrru ehllo ist no ``` I want to make it so that when I arrange the words in ArrayList two into alphabetical order, all the words from ArrayList one follow suite: ``` ArrayList1 ..... ArrayList2 Yes-Man ........ aemnsy MURDER! ........ demrru Hello .......... ehllo It's ........... ist ON ............. no ``` I tried to make a loop with a for statement or two, but it ended up not working and became very long. How do I do this? How do I do this efficiently?

Original source