/**
 * This interface encapsulates what a class used in Percolation Threshold
 * simulations should support. By varying the implementations you can
 * experiment with different approaches in analyzing not only what the 
 * Percolation Threshold constants are for different grids, but how efficiently
 * these constants can be determined via simulation.
 * 
 * @author Owen Astrachan
 * @author Jeff Forbes
 * @date March, 2008
 * @date September, 2008
 * @date March, 2011
 */

public interface IPercolate {

	// Possible states for a grid cell are BLOCKED, OPEN, and FULL
    public static final int BLOCKED = 0;
    public static final int OPEN = 1;
    public static final int FULL = 2;

	/**
	 * Open site (row i, col j) if it is not already open.  
     * The method modifies internal state so that determining
     * if percolation occurs could change after taking a step in
     * the simulation.
	 * @param i row index in range [1,N]
	 * @param j column index in range [1,N]
	 */
	public abstract void open(int i, int j); 
	
	/**
	 * Returns true if and only if site (row i, col j) is OPEN
	 */
	public abstract boolean isOpen(int i, int j);

	/**
	 * Returns true if and only if site (row i, col j) is FULL
	 */
	public boolean isFull(int i, int j); 

    /**
     * Returns true if the simulated percolation actually percolates. What it means to
     * percolate could depend on the system being simulated, but returning true
     * typically means there's a connected path from top-to-bottom.
     * @return true iff the simulated system percolates
     */
    public abstract boolean percolates();
}