Sunday, March 30, 2014

Find a line to cut two squares in half

Problem: 

Given two squares on a two dimensional plane, find a line that would cut these two squares in half.

Solution:

Any Line passing the centers of the two squares will cut them in halves. So, we have to connect the lines between the center of the 2 squares. The straight line that connects the two centers of the two squares will cut both of them into half.

Code in java
public class Square {
   public double left;
   public double top;
   public double bottom;
   public double right;
   public Square(double left, double top, double size) {
          this.left = left;
          this.top = top;
          this.bottom = top + size;
          this.right = left + size;
   }

   public Point middle() {
          return new Point((this.left + this.right) / 2,
                                       (this.top + this.bottom) / 2);
   }

   public Line cut(Square other) {
          Point middle_s = this.middle();
          Point middle_t = other.middle();
          if (middle_s == middle_t) {
                 return new Line(new Point(left, top),
                 new Point(right, bottom));
          } else {
                 return new Line(middle_s, middle_t);
          }
   }
}

Note specific to java  - If == operator between the 2 point objects in cut method. I am not sure if it will work, as == operator in java compares references. So, better approach is Point should implement equals() method and compare the 2 point object like this:
if(middle_s.equals(middle_t)){
    ....
}

Thanks.
References :
http://tianrunhe.wordpress.com/2012/04/02/find-a-line-to-cut-two-squares-in-half/
http://stackoverflow.com/questions/6886836/can-i-use-the-operator-to-compare-point-objects-in-java 

Reactions:

0 comments:

Post a Comment