Java中的LZW压缩/扩展

Question

我试图使用LZW code provided by Princeton并对其进行修改，以将码字的大小从9位更改为16位。我不确定如何做到这一点，但我正在考虑使用一个循环，因为在使用之前大小的所有码字时，需要增加大小。我只是在寻找一个有用的方向去做，因为这是一个任务，我有困难开始

public class LZW {
    private static final int R = 256;        // number of input chars
    private static final int L = 4096;       // number of codewords = 2^W
    private static final int W = 12;         // codeword width

public static void compress() { 
    String input = BinaryStdIn.readString();
    TST<Integer> st = new TST<Integer>();
    for (int i = 0; i < R; i++)
        st.put("" + (char) i, i);
    int code = R+1;  // R is codeword for EOF

    while (input.length() > 0) {
        String s = st.longestPrefixOf(input);  // Find max prefix match s.
        BinaryStdOut.write(st.get(s), W);      // Print s's encoding.
        int t = s.length();
        if (t < input.length() && code < L)    // Add s to symbol table.
            st.put(input.substring(0, t + 1), code++);
        input = input.substring(t);            // Scan past s in input.
    }
    BinaryStdOut.write(R, W);
    BinaryStdOut.close();
} 


public static 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 = BinaryStdIn.readInt(W);
    if (codeword == R) return;           // expanded message is empty string
    String val = st[codeword];

    while (true) {
        BinaryStdOut.write(val);
        codeword = BinaryStdIn.readInt(W);
        if (codeword == R) break;
        String s = st[codeword];
        if (i == codeword) s = val + val.charAt(0);   // special case hack
        if (i < L) st[i++] = val + s.charAt(0);
        val = s;
    }
    BinaryStdOut.close();
}



public static void main(String[] args) {
    if      (args[0].equals("-")) compress();
    else if (args[0].equals("+")) expand();
    else throw new IllegalArgumentException("Illegal command line argument");
    }

}