Method normalize

src/main/java/field/utility/Conversions.java:273–301

(List<Class> to, SetMultimap<List<Class>, Conversion> m)

        return d.getShortestPathTo(nto);

    }

    private static List<Class> normalize(List<Class> to, SetMultimap<List<Class>, Conversion> m) {
        if (m.containsKey(to)) return to;

        List<List<Class>> alternatives = new ArrayList<>();
        for (Class c : to) {
            alternatives.add(new ArrayList<>(alternativesFor(c)));
        }

        int[] counts = new int[to.size()];
        while (true) {
            counts[0] += 1;
            int in = 0;
            while (counts[in] > alternatives.get(in)
                    .size() - 1) {
                counts[in] = 0;
                in++;
                if (in > alternatives.size() - 1) return null;
                counts[in]++;
            }

            List<Class> assembled = new ArrayList<>();
            for (int index = 0; index < counts.length; index++) {
                assembled.add(alternatives.get(index)
                                      .get(counts[index]));
            }

            if (m.containsKey(assembled)) return assembled;
        }
    }