如何通过字段相等匹配scala中的两个集合

case class Student(id: Int, name: String)
case class Grade(studentId: Int, score: Double)

val students = List(Student(1, "Alice"), Student(2, "Bob"), Student(3, "Charlie"))
val grades = List(Grade(1, 90.5), Grade(2, 85.0), Grade(4, 78.5))

val matchedStudents = for {
  student <- students
  grade <- grades if student.id == grade.studentId
} yield (student, grade)

matchedStudents.foreach(println)

(Student(1,Alice),Grade(1,90.5))
(Student(2,Bob),Grade(2,85.0))

val gradesMap = grades.groupBy(_.studentId)

val matchedStudentsOptimized = students.flatMap(student => gradesMap.get(student.id).map(student -> _))

matchedStudentsOptimized.foreach(println)