public class Multiway {

    // This class should not be instantiated.
    private Multiway() { }

    // merge together the sorted input streams and write the sorted result to standard output
    private static void merge(In[] streams) {
        int N = streams.length;

        IndexMinPQ<String> pq = new IndexMinPQ<String>(N);
        Out out = new Out("out.txt");
        Out m = new Out("m.txt");

        for (int i = 0; i < N; i++) {
            if (!streams[i].isEmpty()) {
                String key = streams[i].readString();
                pq.insert(i, key);
                out.println("insert " + i + ", " +key);
                }
        }

        Queue<String> minkeys = new Queue<>();

        // Extract and print min and read next from its stream.
        while (!pq.isEmpty()) {

            out.println("MINPQ");
            for (Integer k : pq) {
                out.println(k + ":" +pq.keyOf(k));
            }

            //StdOut.print(pq.minKey() + " ");

            out.println("minkey " + pq.minIndex() + " : " +pq.minKey());
            minkeys.enqueue(pq.minKey());

            for(String el : minkeys)
                m.print(el + " ");


            int i = pq.delMin();
            if (!streams[i].isEmpty()) {
                String key = streams[i].readString();
                pq.insert(i, key);
                out.println("insert " + i + ", " +key);
            }

        }

        StdOut.println();
    }