gistfile1.cs

HuffmanNode F (Queue<HuffmanNode> q1, Queue<HuffmanNode> q2) { 
  return q2.Count == 0 || (q1.Count > 0 && q2.Count > 0 && q1.Peek ().v < q2.Peek ().v) ? 
    q1.Dequeue () : 
    q2.Dequeue (); 
}

public HuffmanNode GetTree (string data) {
  Queue<HuffmanNode> p = new Queue<HuffmanNode> (Frequencies (data));
  Queue<HuffmanNode> q = new Queue<HuffmanNode> ();
  while (p.Any () || q.Count > 1) { 
   HuffmanNode l = F (p, q), r = F (p, q), t = l + r;
   q.Enqueue (t); 
  }
  return q.Dequeue ();
}

gistfile2.java

/**
   * Decides which queue we should dequeue a node from when building the tree—the first queue represents the original 
   * nodes, the second queue contains portions of the tree as it's built.
   */
  private static HuffmanNode chooseNodeFromQueues (Queue<HuffmanNode> first, Queue<HuffmanNode> second) {
    return (second.size () == 0 || (first.size () > 0 && second.size () > 0 && first.peek ().value < second.peek ().value)) ?
      first.remove () :
      second.remove ();
  }
  
  /**
   * Converts a frequency map to a node queue.
   */
  private static Queue<HuffmanNode> frequencyMapToQueue (Map<Character, Integer> frequencyMap) {
    Queue<HuffmanNode> queue = new LinkedList<HuffmanNode> ();
    for (Map.Entry<Character, Integer> e : frequencyMap.entrySet ()) {
      HuffmanNode h = new HuffmanNode ();
      h.character = e.getKey ();
      h.value = e.getValue ();
      queue.add (h);
    }
    System.out.println (queue.size ());
    return queue;
  }
  
  /**
   * Converts a frequency map to a Huffman tree.
   */
  public static HuffmanNode frequencyMapToHuffmanTree (Map<Character, Integer> frequencyMap) {
    Queue<HuffmanNode> primary = frequencyMapToQueue (frequencyMap);
    Queue<HuffmanNode> secondary = new LinkedList<HuffmanNode> ();
    while (primary.size () > 0 || secondary.size () > 1) {
      HuffmanNode left = chooseNodeFromQueues (primary, secondary);
      HuffmanNode right = chooseNodeFromQueues (primary, secondary);
      System.out.println ("Nodes picked: " + left.character + " and " + right.character);
      HuffmanNode newNode = new HuffmanNode ();
      newNode.left = left;
      newNode.right = right;
      newNode.character = null;
      newNode.value = left.value + right.value;
      secondary.add (newNode);
    }
    return secondary.remove ();
  }