Question

I have some arraylist string with keyword inside like that !

A windows is arraylist string with keyword is bold
Struct of window : 9 words before + keyword + 9 words after

You can see some window overlaping

How to i combine that arraylist to receive like that :

Thanks

Answer 1

If you’re not too worried about performance, a simple subList/equals matching is very easy to write:

    String[] texts = {
        "sunset lake michigan michigan alaska water florida "
        + "peninsula third largest water seventh largest water "
        + "percentage edit list largest country",

        "michigan alaska water florida peninsula third largest water "
        + "seventh largest water percentage edit list largest country "
        + "subdivision list political",

        "third largest water seventh largest water percentage edit list "
        + "largest country subdivision list political geographic "
        + "subdivisions total edit references"
    };
    List<String> joined = new ArrayList<String>();
    for (String text : texts) {
        List<String> textAsList = Arrays.asList(text.split(" "));
        final int N = joined.size();
        final int M = textAsList.size();
        for (int k = Math.min(N, M); k >= 0; k--) {
            if (joined.subList(N - k, N).equals(textAsList.subList(0, k))) {
                joined.addAll(textAsList.subList(k, M));
                break;
            }
        }
    }
    System.out.println(joined);

This prints:

[sunset, lake, michigan, michigan, alaska, water, florida,
peninsula, third, largest, water, seventh, largest, water,
percentage, edit, list, largest, country, subdivision, list,
political, geographic, subdivisions, total, edit, references]

The algorithm works as it says: to build List<String> joined, given a List<String> textAsList, we find the longest subList matching between the “tail” of joined and the “head” of textAsList.