Listar por curso

Parte de la sección Lógica y flujo del Journey de GDScript de Coddy. Lección 47 de 78.

Desafío

Fácil

Enumera los estudiantes que cursan una asignatura. Conserva todo lo que escribiste en los pasos anteriores.

1. La función. Debajo de las otras funciones, escribe list_students_by_course(course: String) -> Array. Recorre student_records y devuelve un array con los nombres de los estudiantes cuyo conjunto "courses" contiene la asignatura, en el orden en que se añadieron los estudiantes. Cuando nadie cursa la asignatura, devuelve un array vacío.

2. El comando. Añade una rama para course <course>, como course Math, antes de ["show"]. Imprime el array que devuelve list_students_by_course(). Para los comandos

add Alice 20 Math Physics
add Bob 22 Math Biology
add Diana 23 Chemistry Physics
course Math
course Physics
course Biology
course History
exit

la salida es:

Student 'Alice' added successfully.
Student 'Bob' added successfully.
Student 'Diana' added successfully.
["Alice", "Bob"]
["Alice", "Diana"]
["Bob"]
[]
Goodbye!

Pruébalo tú mismo

extends Node

# Cada estudiante: nombre -> {"age": int, "grades": Array, "courses": un conjunto de nombres de cursos}
var student_records := {}

func _ready():
	while true:
		var parts := Array(OS.read_string_from_stdin().split(" ", false))
		match parts:
			["add", var student, var age, ..]:
				add_student(student, int(age), parts.slice(3))
			["grade", var student, var grade]:
				add_grade(student, int(grade))
			["enrolled", var student, var course]:
				print(is_enrolled(student, course))
			["average", var student]:
				var average := calculate_average_grade(student)
				if average >= 0:
					print("Average grade of '%s': %.2f" % [student, average])
			["show"]:
				print(student_records)
			["exit"]:
				print("Goodbye!")
				break

func add_student(student_name: String, age: int, courses: Array) -> void:
	if student_records.has(student_name):
		print("Student '%s' already exists." % student_name)
		return
	var course_set := {}
	for course in courses:
		course_set[course] = true
	student_records[student_name] = {"age": age, "grades": [], "courses": course_set}
	print("Student '%s' added successfully." % student_name)

func add_grade(student_name: String, grade: int) -> void:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return
	student_records[student_name]["grades"].append(grade)
	print("Grade %d added for student '%s'." % [grade, student_name])

func is_enrolled(student_name: String, course: String) -> bool:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return false
	return student_records[student_name]["courses"].has(course)

func calculate_average_grade(student_name: String) -> float:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return -1.0
	var grades: Array = student_records[student_name]["grades"]
	if grades.is_empty():
		return 0.0
	var total := 0
	for grade in grades:
		total += grade
	return float(total) / grades.size()