/// <summary>
/// Reads a sequence of 8-bit bytes from standard input; compresses
/// them using LZW compression with 12-bit codewords; and writes the results
/// to standard output.</summary>
///
public void Compress()
{
string inputChars = input.ReadString();
TST <int> st = new TST <int>();
for (int i = 0; i < R; i++)
{
st.Put("" + (char)i, i);
}
int code = R + 1; // R is codeword for EOF
while (inputChars.Length > 0)
{
string s = st.LongestPrefixOf(inputChars); // Find max prefix match s.
output.Write(st[s], W); // Print s's encoding.
int t = s.Length;
if (t < inputChars.Length && code < L) // Add s to symbol table.
{
st.Put(inputChars.Substring(0, t + 1), code++);
}
inputChars = inputChars.Substring(t); // Scan past s in input.
}
output.Write(R, W);
output.Close();
}
public static void MainTest(string[] args)
{
// build symbol table from standard input
TST <int> st = new TST <int>();
TextInput StdIn = new TextInput();
for (int i = 0; !StdIn.IsEmpty; i++)
{
string key = StdIn.ReadString();
st.Put(key, i);
//Console.WriteLine("Key, value = {0}, {1} is {2}", key, st[key], st[key] == i);
}
// print results
if (st.Count < 100)
{
Console.WriteLine("keys(\"\"):");
foreach (string key in st.Keys)
{
Console.WriteLine(key + " " + st[key]);
}
Console.WriteLine();
}
Console.WriteLine("LongestPrefixOf(\"shellsort\"):");
Console.WriteLine(st.LongestPrefixOf("shellsort"));
Console.WriteLine();
Console.WriteLine("LongestPrefixOf(\"quicksort\"):");
Console.WriteLine(st.LongestPrefixOf("quicksort"));
Console.WriteLine();
Console.WriteLine("KeysWithPrefix(\"shor\"):");
foreach (string s in st.KeysWithPrefix("shor"))
{
Console.WriteLine(s);
}
Console.WriteLine();
Console.WriteLine("KeysThatMatch(\".he.l.\"):");
foreach (string s in st.KeysThatMatch(".he.l."))
{
Console.WriteLine(s);
}
Console.WriteLine();
}