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)
        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
            For Each JukugoRight As String In JukugoList '右
                For Each JukugoBottom As String In JukugoList '下
                    For Each JukugoLeft As String In JukugoList '左
                        If JukugoTop.Substring(3, 1) = JukugoRight.Substring(0, 1) AndAlso _
                        JukugoRight.Substring(3, 1) = JukugoBottom.Substring(3, 1) AndAlso _
                        JukugoBottom.Substring(0, 1) = JukugoLeft.Substring(3, 1) AndAlso _
                        JukugoLeft.Substring(0, 1) = JukugoTop.Substring(0, 1) Then
                            If JukugoTop.Substring(3, 1) <> JukugoBottom.Substring(0, 1) 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
                Next
            Next
        Next
    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