public BinaryTreeNode <CharFreq> Build(List <CharFreq> charFreq, int n)
{
PriorityQueue Q = new PriorityQueue();
for (int i = 0; i < n; i++)
{
BinaryTreeNode <CharFreq> z = new BinaryTreeNode <CharFreq>(charFreq[i]);
Q.insert(z);
}
Q.buildHeap();
for (int i = 0; i < n - 1; i++)
{
BinaryTreeNode <CharFreq> x = Q.extractMin();
BinaryTreeNode <CharFreq> y = Q.extractMin();
CharFreq chFreq = new CharFreq();
chFreq.ch = (char)((int)x.Value.ch + (int)y.Value.ch);
chFreq.freq = x.Value.freq + y.Value.freq;
BinaryTreeNode <CharFreq> z = new BinaryTreeNode <CharFreq>(chFreq);
z.Left = x;
z.Right = y;
Q.insert(z);
}
return(Q.extractMin());
}
private void preobr_Click(object sender, EventArgs e)
{
string s = tb1.Text;
int n = s.Length;
List <CharFreq> list = new List <CharFreq>();
tb2.Text = string.Empty;
for (int i = 0; i < n; i++)
{
bool found = false;
char c = s[i];
CharFreq cf = new CharFreq();
for (int j = 0; !found && j < list.Count; j++)
{
if (c == list[j].ch)
{
found = true;
cf.ch = c;
cf.freq = 1 + list[j].freq;
list.RemoveAt(j);
list.Add(cf);
}
}
if (!found)
{
cf.ch = c;
cf.freq = 1;
list.Add(cf);
}
}
HuffmanTree ht = new HuffmanTree();
BinaryTreeNode <CharFreq> root = ht.Build(list, list.Count);
InorderTraversal(root);
tb2.Text += "\r\n characters = " + n.ToString() + "\r\n";
tb2.Text += " leaf nodes = " + leafNodes.ToString() + "\r\n";
tb2.Text += "\r\n % compressed = " +
(100.0 - 100.0 * ((double)leafNodes) / n).ToString("F2") + "\r\n";
}
private void InorderTraversal(BinaryTreeNode <CharFreq> node)
{
if (node != null)
{
InorderTraversal(node.Left);
CharFreq cf = node.Value;
int ord = (int)cf.ch;
if (node.Left == null && node.Right == null)
{
leafNodes++;
tb2.Text += "'" + new string(cf.ch, 1) + "' ";
tb2.Text += node.Value.freq.ToString() + "\r\n";
}
InorderTraversal(node.Right);
}
}