PercolationVisualizer.java

import java.awt.Font;

import edu.princeton.cs.algs4.In;
import edu.princeton.cs.algs4.StdDraw;

public class PercolationVisualizer {
    // delay in miliseconds (controls animation speed)
    private static final int DELAY = 100;

    // draw N-by-N percolation system
    public static void draw(Percolation perc, int N) {
        StdDraw.clear();
        StdDraw.setPenColor(StdDraw.BLACK);
        StdDraw.setXscale(0, N);
        StdDraw.setYscale(0, N);
        StdDraw.filledSquare(N / 2.0, N / 2.0, N / 2.0);

        // draw N-by-N grid
        int opened = 0;
        for (int row = 1; row <= N; row++) {
            for (int col = 1; col <= N; col++) {
                if (perc.isFull(row, col)) {
                    StdDraw.setPenColor(StdDraw.BOOK_LIGHT_BLUE);
                    opened++;
                } else if (perc.isOpen(row, col)) {
                    StdDraw.setPenColor(StdDraw.WHITE);
                    opened++;
                } else {
                    StdDraw.setPenColor(StdDraw.BLACK);
                }
                StdDraw.filledSquare(col - 0.5, N - row + 0.5, 0.45);
            }
        }

        // write status text
        StdDraw.setFont(new Font("SansSerif", Font.PLAIN, 12));
        StdDraw.setPenColor(StdDraw.BLACK);
        StdDraw.text(.25 * N, -N * .025, opened + " open sites");
        if (perc.percolates()) {
            StdDraw.text(.75 * N, -N * .025, "percolates");
        } else {
            StdDraw.text(.75 * N, -N * .025, "does not percolate");
        }

    }

    public static void main(String[] args) {
        In in = new In(args[0]); // input file
        int N = in.readInt(); // N-by-N percolation system

        // turn on animation mode
        StdDraw.show(0);

        // repeatedly read in sites to open and draw resulting system
        Percolation perc = new Percolation(N);
        draw(perc, N);
        StdDraw.show(DELAY);
        while (!in.isEmpty()) {
            int i = in.readInt();
            int j = in.readInt();
            perc.open(i, j);
            draw(perc, N);
            StdDraw.show(DELAY);
        }
    }

    public void show(int i) {
        StdDraw.show(i);
    }
}