fixed all problems from graded feedback

338/homework5/School.java

@@ -93,16 +93,7 @@ public class School {
 		return true;
 	}
 
-	public int courseEnrolled(int id) {
-		// Helper function which simply counts up how many people are enrolled in a given cuorse
-		int count = 0;
-		for(Course i : this.courseList) {
-			if(i.id == id) {
-				count++;
-			}
-		}
-		return count;
-	}
+
 
 	public String getInstructor(int id) {
 		// find the instructor name given an id
@@ -131,6 +122,16 @@ public class School {
 
 		return sum / (float)count;
 	}
+	public int courseEnrolled(int id) {
+		int count = 0;
+		for(Student s : this.studentList) {
+			// everytime a student has the given id in their grades add 1 to the counter
+			if(s.grades.get(id) != null) {
+				count++;
+			}
+		}
+		return count;
+	}
 	
 	public void courseInfo(int id) {
 		boolean found = false;
@@ -168,18 +169,24 @@ public class School {
 	public boolean courseEmpty(int courseID) {
 		for(Student s : this.studentList) {
 			if(s.grades.get(courseID) != null) {
-				return true;
+				return false;
 			}
 		}
 		return true;
 	}
 	public boolean deleteCourse(int id) {
-		for(int i =0;i<this.courseList.size();i++) {
-			if(this.courseEmpty(this.courseList.get(i).id)) {
-				if(this.courseList.get(i).id == id) {
-					this.courseList.remove(i);
-					return true;
+		if(!courseEmpty(id)) {
+			System.out.println("Course " + id + " is not empty!");
+			return false;
 		}
+		// next look for the course to delete
+		for(int i =0; i<courseList.size();i++) {
+			if(courseList.get(i).id == id) {
+				courseList.remove(i);
+				for(Student s : studentList) {
+					s.grades.remove(id);
+				}
+				return true;
 			}
 		}
 		return false;
@@ -248,10 +255,19 @@ public class School {
 		return true;
 	}
 	public void drop(int studentID, int courseID) {
+		for(Student s : studentList) {
+			if(s.id == studentID) {
+				s.grades.remove(courseID);
+			}
+		}
 	}
 	public void assign(int instructorID, int courseID) {
+		Course c = getCourse(courseID);
+		c.instructorID = instructorID;	
 	}
 	public void unassign(int instructorID, int courseID) {
+		Course c = getCourse(courseID);
+		c.instructorID = 0;
 	}
 	// basic printout of school infor
 	public void schoolInfo() {