Imports System
Imports System.Collections.Generic
Module Program
Function ProductsNConsecutiveItems(lst As List(Of Integer),
nConsecutiveItems As Integer) As List(Of Integer)
Dim products As New List(Of Integer)()
If nConsecutiveItems <= 0 OrElse lst.Count < nConsecutiveItems Then
Return products ' empty
End If
Dim outSize As Integer = lst.Count - nConsecutiveItems + 1
For i As Integer = 0 To outSize - 1
Dim prod As Integer = 1
' Multiply lst(i) * lst(i+1) * ... * lst(i+nConsecutiveItems-1)
For j As Integer = 0 To nConsecutiveItems - 1
prod *= lst(i + j)
Next
products.Add(prod)
'
' Example for nConsecutiveItems = 3:
' 2 * 3 * 4 = 24
' 3 * 4 * 5 = 60
' 4 * 5 * 6 = 120
' 5 * 6 * 7 = 210
' 6 * 7 * 8 = 336
' 7 * 8 * 9 = 504
' 8 * 9 * 10 = 720
'
Next
Return products
End Function
Sub Main()
Dim lst As New List(Of Integer) From {2, 3, 4, 5, 6, 7, 8, 9, 10}
Dim n As Integer = 3
Dim products As List(Of Integer) = ProductsNConsecutiveItems(lst, n)
Console.Write("[")
For i As Integer = 0 To products.Count - 1
Console.Write(products(i))
If i < products.Count - 1 Then Console.Write(", ")
Next
Console.WriteLine("]")
End Sub
End Module
' run:
'
' [24, 60, 120, 210, 336, 504, 720]
'
