Imports System
Imports System.Collections.Generic
Public Module Module1
Private Function getMoreThanOnce(ByVal arr As Integer()) As Dictionary(Of Integer, Integer)
Dim map As Dictionary(Of Integer, Integer) = New Dictionary(Of Integer, Integer)()
Dim len As Integer = arr.Length
For i As Integer = 0 To len - 1
If map.ContainsKey(arr(i)) Then
Dim count = map(arr(i))
map.Remove(arr(i))
map.Add(arr(i), count + 1)
Else
map.Add(arr(i), 1)
End If
Next
Return map
End Function
Public Sub Main()
Dim arr As Integer() = {1, 6, 3, 1, 8, 9, 9, 1, 3, 4}
Dim map As Dictionary(Of Integer, Integer) = New Dictionary(Of Integer, Integer)()
map = getMoreThanOnce(arr)
For Each e As KeyValuePair(Of Integer, Integer) In map
If e.Value > 1 Then
Console.Write(e.Key & " ")
End If
Next
End Sub
End Module
' run:
'
' 1 3 9
'
