Numbers & Numbers

[Terry Olsen]

I have an array filled with counts of numbers. Example:

ar(1) contains the number of occurrances of the number 1
ar(2) contains the number of occurrances of the number 2
etc...

I need to find the 10 numbers with the highest occurrances.

I must be overlooking something but i've been beating my head against the
wall for a couple of hours now playing with arrays. Someone point me in the
right direction?

[rowe_newsgroups]

On Nov 12, 1:35 am, "Terry Olsen" <[e-mail]:

I have an array filled with counts of numbers. Example:

ar(1) contains the number of occurrances of the number 1
ar(2) contains the number of occurrances of the number 2
etc...

I need to find the 10 numbers with the highest occurrances.

I must be overlooking something but i've been beating my head against the
wall for a couple of hours now playing with arrays. Someone point me in the
right direction?

This seems like huge overkill, but if I understood your problem it's
the first thing that came to mind. Basically, I transformed the
original array into a list of KeyValue pairs (to maintain the index in
the original array), sorted the List with a custom comparer, and
turned it back into an array. The following is a Console project, just
copy and paste it in and you'll see what I mean:

////////////////////////
Module Module1

Sub Main()
'// Demo array
Dim array As Integer() = {73, 5, 13, 41, 2, 4, 53, 42, 14, 15,
16, 67}

'// Our List
Dim list As New List(Of KeyValuePair(Of Integer, Integer))

'// Move the array to the list
For i As Integer = 0 To array.Length - 1
list.Add(New KeyValuePair(Of Integer, Integer)(i,
array(i)))
Next

'// Sort the List by Values
list.Sort(New MyComparer())

'// Move the List back to an Array
Dim newArray As KeyValuePair(Of Integer, Integer)() =
list.ToArray()

'// Print the top 10 results
For i As Integer = 0 To 9
Console.WriteLine("{0} with {1} occurrances",
newArray(i).Key, newArray(i).Value)
Next

Console.Read()

End Sub
End Module

Public Class MyComparer
Implements IComparer(Of KeyValuePair(Of Integer, Integer))

Public Function Compare(ByVal x As
System.Collections.Generic.KeyValuePair(Of Integer, Integer), ByVal y
As System.Collections.Generic.KeyValuePair(Of Integer, Integer)) As
Integer Implements System.Collections.Generic.IComparer(Of
System.Collections.Generic.KeyValuePair(Of Integer, Integer)).Compare
If x.Value = y.Value Then
Return 0
ElseIf x.Value < y.Value Then
Return 1
Else
Return -1
End If
End Function

End Class
////////////////////////

Thanks,

Seth Rowe

[=?Utf-8?B?QU1lcmNlcg==?=]

I have an array filled with counts of numbers. Example:

ar(1) contains the number of occurrances of the number 1
ar(2) contains the number of occurrances of the number 2
etc...
I need to find the 10 numbers with the highest occurrances.

Dim ir(UBound(ar)) As Integer
For i As Integer = LBound(ir) To UBound(ir) : ir(i) = i : Next
Array.Sort(ar, ir)

If n is ubound(ar), then ar(n) is the max frequency, and ir(n) is the number
having that frequency. ar(n-1) is the 2nd highest frequency, and ir(n-1) is
the number having that frequency. And so on.

As written, ar() is destroyed. If you need to preserve it, you should sort
an ar() clone.