Imports System
Imports System.Collections.Generic
Class Program
Public Shared Sub Main()
Dim matrix As Integer(,) = {
{1, 2, 3},
{4, 5, 6},
{7, 8, 7}}
For i As Integer = 0 To matrix.GetLength(0) - 1
If RowHasRepetitions(matrix, i) Then
Console.WriteLine($"Row {i} contains repetitions.")
Else
Console.WriteLine($"Row {i} has unique numbers.")
End If
Next
If IsMatrixValid(matrix) Then
Console.WriteLine("All rows in the matrix contain unique numbers.")
Else
Console.WriteLine("Some rows in the matrix contain repeated numbers.")
End If
End Sub
Private Shared Function RowHasRepetitions(ByVal matrix As Integer(,), ByVal rowIndex As Integer) As Boolean
Dim seenNumbers As HashSet(Of Integer) = New HashSet(Of Integer)()
For j As Integer = 0 To matrix.GetLength(1) - 1
If Not seenNumbers.Add(matrix(rowIndex, j)) Then
Return True
End If
Next
Return False
End Function
Private Shared Function IsMatrixValid(ByVal matrix As Integer(,)) As Boolean
For i As Integer = 0 To matrix.GetLength(0) - 1
If RowHasRepetitions(matrix, i) Then
Return False
End If
Next
Return True
End Function
End Class
' run:
'
' Row 0 has unique numbers.
' Row 1 has unique numbers.
' Row 2 contains repetitions.
' Some rows in the matrix contain repeated numbers.
'
