enum Pattern: String {
    case input = "^[0-9a-zA-Z+]*$"
}

guard let _ = student.range(of: Pattern.input.rawValue, options: .regularExpression),
          student.isEmpty == false else {
    print(Errors.input.rawValue)
    return
}

let isContain = manager.contains { $0.key == student }
    guard isContain == false else {
        print(student, terminator: "")
        Errors.containStudent.printSelf()
        return
    }

let isContain = manager.contains { $0.key == student }
    guard isContain else {
        print("\(student)\(Errors.searchStudent.rawValue)")
        return
    }

var average = 0.0
    for report in reports {
        print("\(report.subject): \(report.grade)")
        switch Grade(rawValue: report.grade) {
        case .APlus:
            average += Score.APlus.rawValue
        case .AZero:
            average += Score.AZero.rawValue
        case .BPlus:
            average += Score.BPlus.rawValue
        case .BZero:
            average += Score.BZero.rawValue
        case .CPlus:
            average += Score.CPlus.rawValue
        case .CZero:
            average += Score.CZero.rawValue
        case .DPlus:
            average += Score.DPlus.rawValue
        case .DZero:
            average += Score.DZero.rawValue
        default:
            average += 0.0
        }
    }
    average /= Double(reports.count)
    print("평점 : \(average)")