package algs34;
import stdlib.*;
import java.util.HashSet;

public final class XGoodPoint {
  static class GoodPoint {
    private final double x;
    private final double y;
    public GoodPoint(double x, double y) { this.x = x; this.y = y; }
    public String toString() { return "(" + x + ", " + y + ")";  }

    public boolean equals(Object other) {
      if (other == this) return true;
      if (other == null || other.getClass() != this.getClass()) return false;
      GoodPoint that = (GoodPoint) other;
      if (Double.compare(this.x,that.x) != 0) return false;
      if (Double.compare(this.y,that.y) != 0) return false;
      return true;
    }
    public int hashCode() {
      int h = 17;
      h = 31*h + Double.hashCode(x);
      h = 31*h + Double.hashCode(y);
      return h;
    }
  }


  public static void main(String[] args) {
    GoodPoint a = new GoodPoint(0.0, 0.0);
    GoodPoint b = new GoodPoint(0.0, 0.0);
    GoodPoint e = new GoodPoint(0.0,-0.0);
    StdOut.format("a = %s [hashcode=%d]\n", a, a.hashCode ());
    StdOut.format("b = %s [hashcode=%d]\n", b, b.hashCode ());
    StdOut.format("e = %s [hashcode=%d]\n", e, e.hashCode ());

    HashSet<GoodPoint> set = new HashSet<>();
    set.add(a);
    StdOut.println("Added a");
    StdOut.println("a == b:      " + (a == b));
    StdOut.println("a.equals(b): " + (a.equals(b)));
    StdOut.println("contains b:  " + set.contains(b));
    StdOut.println("a == e:      " + (a == e));
    StdOut.println("a.equals(e): " + (a.equals(e)));
    StdOut.println("contains e:  " + set.contains(e));
  }
}