Mejores estudiantes

Parte de la sección Lógica y flujo del Journey de GDScript de Coddy. Lección 48 de 78.

Desafío

Fácil

Por último, busca a los mejores estudiantes. Conserva todo lo que escribiste en los pasos anteriores.

1. La función. Debajo de las otras funciones, escribe filter_top_students(threshold: float) -> Array. Devuelve un array con los nombres de los estudiantes cuya nota media es mayor que el umbral, en el orden en que se añadieron. Obtén cada promedio con calculate_average_grade(); un estudiante sin notas tiene un promedio de 0.0.

2. El comando. Añade una rama para top <threshold>, como top 80, encima de ["show"]. Convierte el umbral con float() e imprime el array que devuelve filter_top_students(). Para los comandos

add Alice 20 Math Physics
add Bob 22 Math Biology
add Diana 23 Chemistry Physics
grade Alice 90
grade Alice 85
grade Bob 75
grade Diana 95
top 80
top 90
top 100
exit

el resultado es:

Student 'Alice' added successfully.
Student 'Bob' added successfully.
Student 'Diana' added successfully.
Grade 90 added for student 'Alice'.
Grade 85 added for student 'Alice'.
Grade 75 added for student 'Bob'.
Grade 95 added for student 'Diana'.
["Alice", "Diana"]
["Diana"]
[]
Goodbye!

Tu Student Records Manager ahora combina diccionarios, conjuntos, arrays, funciones y match en un solo programa.

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])
			["course", var course]:
				print(list_students_by_course(course))
			["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()

func list_students_by_course(course: String) -> Array:
	var students_in_course := []
	for student_name in student_records:
		if student_records[student_name]["courses"].has(course):
			students_in_course.append(student_name)
	return students_in_course