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 button1_Click(object sender, EventArgs e)
{
try
{
saveFileDialog1.Filter = "Huffman Files (*.huf)|*.huf";
openFileDialog1.Filter = "Text Files (*.txt)|*.txt";
if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
int[] freq = new int[128];
StreamReader sr = new StreamReader(openFileDialog1.FileName);
iCount = 0;
while (!sr.EndOfStream)
{
int ch = sr.Read();
if (ch >= 0 && ch <= 127)
{
freq[ch]++;
}
else
{
MessageBox.Show("File is not ASCII", "Warning",
MessageBoxButtons.OK, MessageBoxIcon.Warning);
return;
}
iCount++;
}
sr.Close();
charFreq = new List <CharFreq>(128);
for (int i = 0; i < 128; i++)
{
if (freq[i] != 0)
{
CharFreq cf = new CharFreq();
cf.ch = (char)i;
cf.freq = freq[i];
charFreq.Add(cf);
}
}
Compress();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString(), "Warning",
MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
}
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++;
textBox1.Text += ord.ToString("D3") + "\t";
textBox1.Text += cf.freq.ToString() + "\r\n";
}
InorderTraversal(node.Right);
}
}
