Imports System
Imports System.Collections.Generic
Module FloorCeilFinder
' Finds the floor and ceiling of N in the given list
Function FindFloorAndCeil(lst As List(Of Integer), N As Integer) As (Floor As Integer, Ceil As Integer)
Dim floorval As Integer = Integer.MinValue ' Initialize to the smallest possible value
Dim ceilval As Integer = Integer.MaxValue ' Initialize to the largest possible value
For Each num In lst
If num <= N AndAlso num > floorval Then
floorval = num ' Update floorval if num is closer to N
End If
If num >= N AndAlso num < ceilval Then
ceilval = num ' Update ceilval if num is closer to N
End If
Next
' If no valid floorval or ceilval is found, set them to a special value
If floorval = Integer.MinValue Then floorval = -1
If ceilval = Integer.MaxValue Then ceilval = -1
Return (floorval, ceilval)
End Function
Sub Main()
Dim lst As New List(Of Integer) From {4, 10, 8, 2, 6, 9, 1}
Dim N As Integer = 5
Dim result = FindFloorAndCeil(lst, N)
Dim floorval = result.Floor
Dim ceilval = result.Ceil
Console.WriteLine("floor: " & If(floorval = -1, "None", floorval.ToString()))
Console.WriteLine("ceil: " & If(ceilval = -1, "None", ceilval.ToString()))
End Sub
End Module
' run:
'
' floor: 4
' ceil: 6
'
