/* Copyright (C) 2002 J. M. Spivey */

public class Machine {
    public static final int NSTATES = 8, NCOLORS = 4;
    public static final int field = 0, red = 1, green = 2, yellow = 3;
    public static final int left = 0, right = 1, ahead = 2; 

    private int state = 0;  
     
    private int drawtab[][] = new int[NSTATES][NCOLORS];
    private int movetab[][] = new int[NSTATES][NCOLORS];
    private int trantab[][] = new int[NSTATES][NCOLORS];
    
    private void clear() {
        for (int i = 0; i < NSTATES; i++) {
            for (int j = 0; j < NCOLORS; j++) {
                drawtab[i][j] = field;
                movetab[i][j] = left;
                trantab[i][j] = 0;
            }
        }
    }

    public void setup(String desc) {
        int p = 0; char c;
        
        clear();
        for (int i = 0;; i++) {
            for (int j = 0; j < NCOLORS; j++) {
                if (p+3 > desc.length()) return;
                c = desc.charAt(p);
                drawtab[i][j] = 
                    (c == 'r' ? red : c == 'g' ? green 
		     : c == 'y' ? yellow : field);
                c = desc.charAt(p+1);
                movetab[i][j] =
                    (c == 'L' ? left : c == 'R' ? right : ahead);
                c = desc.charAt(p+2);
                trantab[i][j] = (int) c - '1';
                p += 3;
            }
        }
    }
    
    public String descriptor() {
        int N = NSTATES;
        String colors = "brgy";
        String dirs = "LRA";
        
        // Find the last non-trivial state
        while (N > 0) {
            int i = N-1; 
            boolean found = false;
            for (int j = 0; j < NCOLORS && !found; j++) {
                if (drawtab[i][j] != field || movetab[i][j] != left 
		    || trantab[i][j] != 0)
                    found = true;
            }
            if (found) break;
            N--;
        }
        
        StringBuffer buf = new StringBuffer(100);
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < NCOLORS; j++) {
                buf.append(colors.charAt(drawtab[i][j]));
                buf.append(dirs.charAt(movetab[i][j]));
                buf.append(trantab[i][j]+1);
            }
        }
        
        return buf.toString();
    }

    public int getState() { return state; };
    public void reset() { state = 0; }
    
    public void setDraw(int i, int j, int color) { drawtab[i][j] = color; }
    public int getDraw(int i, int j) { return drawtab[i][j]; }
    public void setMove(int i, int j, int n) { movetab[i][j] = n; }
    public int getMove(int i, int j) { return movetab[i][j]; }
    public void setTran(int i, int j, int n) { trantab[i][j] = n; }
    public int getTran(int i, int j) { return trantab[i][j]; }
    
    public int draw(int color) {
        return drawtab[state][color];
    }
    
    public int move(int color) {
        return movetab[state][color];
    }
        
    public void next(int color) {
        state = trantab[state][color];
    }
}