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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));
}
}
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