nextElement

src/train/Railway.java

@@ -26,11 +26,29 @@ public class Railway {
 		boolean first = true;
 		for (Element e : this.elements) {
 			if (first)
-				first = false;
+				first = false; 
 			else
 				result.append("--");
 			result.append(e);
 		}
 		return result.toString();
 	}
+	
+	public Element nextElement(Element currentElement, Direction direction) {
+        if (currentElement == null || direction == null) {
+            throw new NullPointerException("Current element or direction cannot be null.");
+        }
+
+        for (int i = 0; i < elements.length; i++) {
+            if (elements[i] == currentElement) {
+                if (direction == Direction.LR && i < elements.length - 1) {
+                    return elements[i + 1];
+                } else if (direction == Direction.RL && i > 0) {
+                    return elements[i - 1];
+                }
+            }
+        }
+
+        throw new IllegalArgumentException("Current element is not part of the railway or no next element exists in the given direction.");
+    }
 }