lavos/cap3/ex13.go

package cap3

type Subject int
type Student int

func Ex14(subjectPassedStudentMap map[Subject]Student) []Student {
    result := make([]Student, 0)

    // 学生及格科目数记录
    studentRecord := map[Student]int{}
    for _, student := range subjectPassedStudentMap {
        // 对当前学生及格科目计数
        if _, exists := studentRecord[student]; !exists {
            studentRecord[student] = 1
        } else {
            studentRecord[student]++
        }

        // 学生及格科目数已达到传入的科目数，即为全科及格
        if studentRecord[student] == len(subjectPassedStudentMap) {
            result = append(result, student)
        }
    }

    return result
}