str.contains in Java

Question

I am having 2 lists

allWords [book, pen, pencil] 
subsetString [book  pen  , book  pencil  , pen  pencil  ]

I am expecting my output as

book  pen => pencil
book  pencil => pen
pen  pencil => book

ie for each element in subsetString I will be checking it with allwords. Once a match is not found that string from allwords will be added to RHS of output

But my issue is Now I am only getting 2 output instead of 3

allWords [book, pen, pencil]
subsetString [book  pen  , book  pencil  , pen  pencil  ]
pen  pencil   => book
book  pen   => pencil

The reason is while coming into book pencil it get checked with allWords [book, pen, pencil]

once it comes to pen contains book pencil - It is getting satisfed (as pencil contains a substring pen).

CODE

public void getStrongRules2(ArrayList<String> allWords,String delim) {
        ArrayList<ArrayList<String>> subsets = BTSum(allWords);
        ArrayList<String> subsetString = new ArrayList<String>();

        for (int j = 0; j < subsets.size(); j++) {
            String substring = "";
            for (int k = 0; k < subsets.get(j).size(); k++) {

                substring += subsets.get(j).get(k) + "  ";
            }
            subsetString.add(substring);
        }
        System.out.println("allWords "+allWords);
        System.out.println("subsetString "+subsetString);

        for(String a : allWords){
            for (int j = 0; j < subsetString.size(); j++) {
                if (!(subsetString.get(j).contains(a))) {
                    System.out.println(subsetString.get(j)+" => "+a);
                }
            }
        }
    }
    public static ArrayList<ArrayList<String>> BTSum(ArrayList<String> numbers) {

        int n = numbers.size();
        ArrayList<ArrayList<String>> powerSet = new ArrayList<ArrayList<String>>();

        for (long i = 0; i < (1 << n); i++) {
            ArrayList<String> element = new ArrayList<String>();
            for (int j = 0; j < n; j++)
                if ((i >> j) % 2 == 1) {
                    element.add(numbers.get(j));
                }
            if (element.size() > 1 && element.size() < n) {
                powerSet.add(element);
            }
        }
        return powerSet;
    }

}

But this should not happen in my case.

How to rectify that.

Please Suggest

Answer 1

Consider

     List<String> allWords = new ArrayList<>();
     allWords.add("Book"); allWords.add("Pen"); allWords.add("Pencil") ; 

If you can able to Split your Subset into three different lists instead of a single arrayList, Do split Like

     list1 [Book,Pen] 
     list2 [Book,Pencil]
     list3 [Pen,Pencil]

You can follow this without doing loops

     Set<String> results1 = new HashSet<String>(allWords);
     results1.removeAll(list1);
     System.out.println("result1 : "+ list1 +" ===> "+ results1);

     Set<String> results2 = new HashSet<String>(allWords);
     results2.removeAll(list2);
     System.out.println("result2 : "+ list2 +" ===> "+ results2);

     Set<String> results3 = new HashSet<String>(allWords);
     results3.removeAll(list3);
     System.out.println("result3 : "+ list3 +" ===> "+ results3);

Output

result1 : [Book, Pen] ===> [Pencil]
result2 : [Book, Pencil] ===> [Pen]
result3 : [Pen, Pencil] ===> [Book]

Hope this helps