Thursday, October 30, 2014

BouncingBall.java

public class BouncingBall

 public static void main(String[] args)

        StdDraw.setXscale(-1.0, 1.0);

        StdDraw.setYscale(-1.0, 1.0);

        double rx = 0.480, ry = 0.860;

        double vx = 0.015, vy = 0.023;

        double radius = 0.05;

         while (true)

            if (Math.abs(rx + vx) > 1.0 - radius) vx = -vx;

            if (Math.abs(ry + vy) > 1.0 - radius) vy = -vy;

            rx = rx + vx;

            ry = ry + vy;

            StdDraw.setPenColor(StdDraw.GRAY);

            StdDraw.filledSquare(0, 0, 1.0);

            StdDraw.setPenColor(StdDraw.BLACK);

            StdDraw.filledCircle(rx, ry, radius);

            StdDraw.show(20);

PlayThatTune.java

public class PlayThatTune

              public static void main(String[] args)

   while (!StdIn.isEmpty())

           int pitch = StdIn.readInt();

                       double duration = StdIn.readDouble();

                        double hz = 440 * Math.pow(2, pitch / 12.0);

           int N = (int) (StdAudio.SAMPLE_RATE * duration);

           double[] a = new double[N+1];

           for (int i = 0; i <= N; i++)

            a[i] = Math.sin(2 * Math.PI * i * hz / StdAudio.SAMPLE_RATE);

                      StdAudio.play(a);

public class Transition

 public static void main(String[] args)

       int N = StdIn.readInt();

        int[][] counts = new int[N][N];

        int[] outDegree = new int[N];

        while (!StdIn.isEmpty())

            int i = StdIn.readInt();

            int j = StdIn.readInt();

            outDegree[i]++;

            counts[i][j]++;

        StdOut.println(N + " " + N);

                   for (int i = 0; i < N; i++)

                    for (int j = 0; j < N; j++)

                double p = .90*counts[i][j]/outDegree[i] + .10/N;

                StdOut.printf("%7.5f ", p);

            StdOut.println();