import java.io.FileNotFoundException;
import java.io.IOException;

/**
 * The "main" method for the sudoku solver
 */
public class Player {
    public static void main(String[] args) {
        String[] defaults = { "116m.csv" };
        if (args.length == 0)
            args = defaults;
        try {
            GameBoard bg = new GameBoard(args[0]);
            System.out.println(bg.toStringLegal());
            //System.out.println(bg.getLegalMoves());
            new Player().solve(bg);
            //System.out.println(bg.toString());
        } catch (FileNotFoundException fnf) {
            System.err.println(fnf);
        } catch (IOException ioe) {
            System.err.println(ioe);
        } catch (ArrayIndexOutOfBoundsException ai) {
            System.err.println(ai);
        }
        
    }


    int rcount = 0; // a count of the number of recursions
    // because of backtracking this needs to be counted outside the 
    // recursive process
    public void solve(GameBoard gb) {
        rcount = 0;
        GameBoard ngb = solveUtil(gb, 0,0);
        if (ngb!=null)
            System.out.println(ngb);
        System.out.println(rcount);
    }

    // the recursive solver!!!
    public GameBoard solveUtil(GameBoard gb, int xx, int yy) {
        if (gb.noZeros())
            return gb;  // solution reached!!!!
        if (yy>=9) {
            yy=0;
            xx++;
            if (xx>=9)
                return null;
        }
        rcount++;
        if ((rcount % 1000) == 0)
            System.out.println(rcount);
        //System.out.println(this.toString());
        if (!gb.solvable()) {  
            //System.out.println("    NOT");
            return null;
        }
        if (gb.board[xx][yy].value >0)  // this position is already occupied, so go on
            return solveUtil(gb,xx, yy+1);
        //System.out.println(xx + " " + yy + " " + gb.board[xx][yy]);
        for (int m=0; m<9; m++) {
            if (gb.board[xx][yy].legalMoves[m]) {
                //System.out.println("Trying " + xx + " " + yy + " " + (m+1));
                gb.board[xx][yy].value=(m+1);  // m+1 because of arrays starting at 0.
                GameBoard ngb = solveUtil(new GameBoard(gb), xx, yy+1);
                if (ngb!=null)
                    return ngb;
            }
        }
        return null;
    }
    
}