Solution for Comparators 01

Coordinate.java

@@ -0,0 +1,32 @@
+public class Coordinate implements Comparable<Coordinate> {
+
+  private int x;
+  private int y;
+
+  public Coordinate(int x, int y) {
+    this.x = x;
+    this.y = y;
+  }
+
+  public int getX() {
+    return x;
+  }
+
+  public int getY() {
+    return y;
+  }
+
+  public double getDistanceToOriginPoint() {
+    return Math.hypot(x, y);
+  }
+
+  public int compareTo(Coordinate c) {
+    if (getDistanceToOriginPoint() < c.getDistanceToOriginPoint()) {
+      return -1;
+    } else if (getDistanceToOriginPoint() > c.getDistanceToOriginPoint()) {
+      return 1;
+    } else {
+      return 0;
+    }
+  }
+}

Exercise.java

@@ -1,6 +1,21 @@
+import java.util.ArrayList;
+import java.util.Collections;
+
 public class Exercise {
 
   public static void main(String[] args) {
-    // implement exercise here
+    ArrayList<Coordinate> coordinates = new ArrayList<>();
+
+    coordinates.add(new Coordinate(3, 5));
+    coordinates.add(new Coordinate(7, 6));
+    coordinates.add(new Coordinate(2, 1));
+    coordinates.add(new Coordinate(6, 8));
+    coordinates.add(new Coordinate(1, 9));
+
+    Collections.sort(coordinates);
+
+    for (Coordinate c : coordinates) {
+      System.out.println(c + ": " + c.getDistanceToOriginPoint());
+    }
   }
 }