/// <summary>
/// Reads a sequence of bits that represents a Huffman-compressed message from
/// standard input; expands them; and writes the results to standard output.</summary>
///
public void Expand()
{
// read in Huffman trie from input stream
Node root = readTrie();
// number of bytes to write
int length = input.ReadInt();
// decode using the Huffman trie
for (int i = 0; i < length; i++)
{
Node x = root;
while (!x.IsLeaf)
{
bool bit = input.ReadBoolean();
if (bit)
{
x = x.right;
}
else
{
x = x.left;
}
}
output.Write(x.ch, 8);
}
output.Close();
}
/// <summary>
/// Reads a sequence of bit encoded using LZW compression with
/// 12-bit codewords from standard input; expands them; and writes
/// the results to standard output.</summary>
///
public void Expand()
{
string[] st = new string[L];
int i; // next available codeword value
// initialize symbol table with all 1-character strings
for (i = 0; i < R; i++)
{
st[i] = "" + (char)i;
}
st[i++] = ""; // (unused) lookahead for EOF
int codeword = input.ReadInt(W);
if (codeword == R)
{
return; // expanded message is empty string
}
string val = st[codeword];
while (true)
{
output.Write(val);
codeword = input.ReadInt(W);
if (codeword == R)
{
break;
}
string s = st[codeword];
if (i == codeword)
{
s = val + val[0]; // special case hack
}
if (i < L)
{
st[i++] = val + s[0];
}
val = s;
}
output.Close();
}
/// <summary>
/// Reads a binary sequence from standard input; converts each two bits
/// to an 8-bit extended ASCII character over the alphabet { A, C, T, G };
/// and writes the results to standard output.</summary>
///
public void Expand()
{
int N = input.ReadInt();
// Read two bits; write char.
for (int i = 0; i < N; i++)
{
char c = input.ReadChar(2);
output.Write(DNA.ToChar(c), 8);
}
output.Close();
input.Close();
}
/// <summary>Reads a sequence of bits from standard input (that are encoded
/// using run-length encoding with 8-bit run lengths); decodes them;
/// and writes the results to standard output.</summary>
///
public void Expand()
{
bool b = false;
while (!input.IsEmpty)
{
int run = input.ReadInt(LG_R);
for (int i = 0; i < run; i++)
{
output.Write(b);
}
b = !b;
}
output.Close();
}
