Module Module1

    Sub Main(ByVal args() As String) '引数に四字熟語をCRLFで区切り列挙したテキストファイルを指定。文字コードはUnicode。ファイルは複数指定可能。
        Dim Ticks As Long = Now.Ticks
        Dim JukugoList As New List(Of String) '四字熟語のリスト  
        '四字熟語リストの読み込みループ
        For Each CmdLine As String In args
            JukugoList.AddRange(System.IO.File.ReadAllLines(CmdLine))
        Next
        JukugoPuzul(JukugoList)
        Console.WriteLine((Now.Ticks - Ticks) / 10000000L & "秒")
        Console.ReadKey()
    End Sub

    Private Sub JukugoPuzul(ByVal JukugoList As List(Of String))
        Dim Kouho As New List(Of String())
        For Each JukugoTop As String In JukugoList '上
            Dim Top() As Char = JukugoTop.ToCharArray
            For Each JukugoRight As String In JukugoList '右
                Dim Right() As Char = JukugoRight.ToCharArray
                If Top(3) = Right(0) Then
                    For Each JukugoBottom As String In JukugoList '下
                        Dim Bottom() As Char = JukugoBottom.ToCharArray
                        If Right(3) = Bottom(3) Then
                            For Each JukugoLeft As String In JukugoList '左
                                Dim Left() As Char = JukugoLeft.ToCharArray
                                If Bottom(0) = Left(3) AndAlso _
                                Left(0) = Top(0) Then
                                    If Top(3) <> Bottom(0) Then '右上隅の漢字と左下隅の漢字は異なるものでなければいけません。
                                        Dim Group() As String = {JukugoTop, JukugoRight, JukugoBottom, JukugoLeft}
                                        If ChofukuCheck(Kouho, Group) Then
                                            OutPut(Group)
                                            Kouho.Add(Group)
                                        End If
                                    End If
                                End If
                            Next
                        End If
                    Next
                End If
            Next
        Next
        Console.WriteLine(Kouho.Count & "組の組み合わせがありました。")
    End Sub

    Private Function ChofukuCheck(ByVal List As List(Of String()), ByVal Kouho As String()) As Boolean
        For Each Group As String() In List
            Dim Count As Integer = 0
            For Each Jukugo As String In Group
                For Each Jukugo1 As String In Kouho
                    If Jukugo = Jukugo1 Then
                        Count += 1
                    End If
                Next
            Next
            If Count = 4 Then
                Return False
            End If
        Next
        Return True
    End Function

    Private Sub OutPut(ByVal Group() As String)
        Console.WriteLine(Group(0))
        Console.WriteLine(Group(3).Substring(1, 1) & "　　" & Group(1).Substring(1, 1))
        Console.WriteLine(Group(3).Substring(2, 1) & "　　" & Group(1).Substring(2, 1))
        Console.WriteLine(Group(2) & vbCrLf)
    End Sub

End Module