mattbarackman · September 12, 2012 02:56 · Sep 12, 2012
diff --git a/StoneMasonKarel.java b/StoneMasonKarel.java
@@ -0,0 +1,153 @@
+/*
+ * File: StoneMasonKarel.java
+ * --------------------------
+ * The StoneMasonKarel subclass as it appears here does nothing.
+ * When you finish writing it, it should solve the "repair the quad"
+ * problem from Assignment 1.  In addition to editing the program,
+ * you should be sure to edit this comment so that it no longer
+ * indicates that the program does nothing.
+ * This sub-class of Karel will repair missing beepers in 
+ * vertical "stone columns". Karel will start at [1,1] 
+ * facing East with an infinite number of Beepers. There is
+ * a column on the 1st avenue and a column every four rows.
+ * The solution will accomodate any number of columns and 
+ * the columns can be of any height. Each column will have 
+ * some (but not all) Beepers (stones) in their correct
+ * places, so Karel will need to pass over these without
+ * doubling them. 
+ * 
+ * Matt Barackman
+ * 9.3.2012
+ */
+
+import stanford.karel.*;
+
+public class StoneMasonKarel extends SuperKarel {
+
+	/* METHOD: run()
+	 * 
+	 * Karel will repair a column, walk to the next column,
+	 * repair that column, and repeat until he hits a wall. 
+	 *  
+	 * pre-condition: 
+	 * Karel is at the far left corner of bottom row facing East,
+	 * standing on a broken column.
+	 * 
+	 * post-condition:
+	 * Karel is standing at the far-right corner of the first row, 
+	 * facing east, having repaired all the columns.
+	 */
+
+	public void run() {
+		repairColumn();
+		while (frontIsClear()){
+			moveToNextColumn();
+			repairColumn();
+		}
+	}
+
+	/* METHOD: moveToNextColumn()
+	 * 
+	 * Karel will move forward four spaces to the next column.
+	 * Columns must be exactly four spaces apart.
+	 *  
+	 * pre-condition: 
+	 * Karel is standing on a column (hopefully fixed) facing East.
+	 * 
+	 * post-condition:
+	 * Karel is standing on the next column, still facing East.
+	 */
+
+	private void moveToNextColumn() {
+		move();
+		move();
+		move();
+		move();
+	}
+
+	/* METHOD: repairColumn()
+	 * 
+	 * Karel will turn, ascend the column, repairing it as he goes,
+	 * then descend the column, and turn to East again.
+	 *  
+	 * pre-condition: 
+	 * Karel is standing on a partially broken column facing East.
+	 * 
+	 * post-condition:
+	 * Karel is standing on the same spot, facing East, with the
+	 * column now repaired.
+	 */
+
+	private void repairColumn() {
+		ascendColumn();
+		descendColumn();
+	}
+
+	/* METHOD: ascendColumn()
+	 * Karel will turn left, ascend the column, and place a single
+	 * beeper in all the empty spaces.
+	 *  
+	 * pre-condition: 
+	 * Karel is standing on a partially broken column facing East.
+	 * 
+	 * post-condition:
+	 * Karel is standing at the top of a column, facing North, with
+	 * the column now repaired.
+	 */
+
+	private void ascendColumn() {
+		turnLeft();
+		while (frontIsClear()){
+			placeBeeperIfEmpty();
+			move();
+		}
+		placeBeeperIfEmpty();
+	}
+
+
+	/* METHOD: placeBeeperIfEmpty()
+	 * 
+	 * Karel will place a beeper if standing on an empty square.
+	 *  
+	 */
+
+	private void placeBeeperIfEmpty(){
+		if (noBeepersPresent()){
+			putBeeper();
+		}	
+	}
+
+	/* METHOD: descendColumn()
+	 * 
+	 * Karel will turn around, descend the column, and turn left to 
+	 * face East.
+	 *  
+	 * pre-condition: 
+	 * Karel is standing at the top of a repaired column facing
+	 * North.
+	 * 
+	 * post-condition:
+	 * Karel is standing at the bottom of the repaired column 
+	 * facing East.
+	 */
+
+	private void descendColumn(){
+		turnAround();
+		moveToWall();
+		turnLeft();
+	}
+
+
+	/* METHOD: descendColumn()
+	 * 
+	 * Karel will will move in whatever direction he is facing
+	 * until he hits a wall.
+	 * 
+	 */
+
+	private void moveToWall(){
+		while (frontIsClear()){
+			move();
+		}	
+	}
+}