Weird TreeSet

        // Input
        String[][] inputs = new String[][]{
                {"one", "two"},
                {"two", "three"},
                {"five", "six"},
                {"six", "one"},
        };

        Map<String, Set<String>> greaterThan = new HashMap<>();

        SortedSet<String> allData = new TreeSet<>((o1, o2) -> {
            if (greaterThan.getOrDefault(o1, Collections.emptySet()).contains(o2))
                return 1;
            else if (greaterThan.getOrDefault(o2, Collections.emptySet()).contains(o1))
                return -1;
            return 0;
        });

        for (String[] pair : inputs) {
            String bigger = pair[0];
            String smaller = pair[1];

            if (!greaterThan.containsKey(bigger))
                greaterThan.put(bigger, new HashSet<>());
            greaterThan.get(bigger).add(smaller);

            allData.add(bigger);
            allData.add(smaller);
            System.out.printf("Bigger: %s\nSmaller: %s\nArray: %s\n\n", bigger, smaller, allData);


        }

        System.out.println(allData);