battleship/Ship.java

public class Ship{
   public static final int X = 0;
   public static final int Y = 1;
   private boolean vertical;
   private int[] start;
   private int[] end;
   private int length;
   public Ship(int[] start,int[] end){
      
      boolean vertical = start[Y] == end[Y];
      this.vertical = vertical;
      int cord;
      if (vertical) {
         cord = X;
      }
      else {
         cord = Y;
      }
      if (start[cord] < end[cord]){
         this.start = start;
         this.end = end;
      }
      else {
         this.start = end;
         this.end = start;
      }
      this.length = this.end[cord] - this.start[cord]+1;
   }
   
   public void print() {
      System.out.println("Start: " + "(" + this.start[X] + ", " + this.start[Y] + ")");
      System.out.println("End: " + "(" + this.end[X] + ", " + this.end[Y] + ")");
   }
   public int getLength() {
      return this.length;
   }
   
   public boolean intersects(Ship other){
      boolean cond1;
      boolean cond2;
      int cord1;
      int cord2;
      // <necessary bit, ensures algorithm works both when other is oriented horizontally or vertically>
      if (other.vertical) {
         cord1 = X;
         cord2 = Y;
      }
      else {
         cord1 = Y;
         cord2 = X;
      }
      // </necessary bit>
      
      // lines are parallel
      if (this.vertical == other.vertical) {
         // System.out.println("parallel");
         
         // overlaps
         cond1 = this.start[cord1] == other.start[cord1];
         
         // intersects
         cond2 = (other.start[cord2] <= this.end[cord2]) || (this.start[cord2] <= other.end[cord2]);
         return cond1 && cond2;
      }
      // lines are perpendicular
      else{
         // System.out.println("perpendicular");
         
         // other in range of this with respect to axis cord1
         cond1 = (this.start[cord1] >= other.start[cord1]) && (this.end[cord1] <= other.end[cord1]);
         // this in range of other with respect to axis cord2
         cond2 = (other.start[cord2] >= this.start[cord2]) && (other.end[cord2] <= this.end[cord2]);
         return cond1 && cond2;
      }
   }
   public static void main(String[] args){
      Ship placedShip1 = new Ship(new int[]{0,0},new int[]{0,2});
      Ship placedShip2 = new Ship(new int[]{1,0},new int[]{1,3});
      placedShip1.print();
      placedShip2.print();
      System.out.println(placedShip1.intersects(placedShip2));
      System.out.println(placedShip1.getLength());
      System.out.println(placedShip2.intersects(placedShip1));
      System.out.println(placedShip2.getLength());
   }
      
}