'///////////////////// BAM - Arrays #4b ///////////////

Public Class Form1
    '//////// GLOBAL DATA

    Const MAXSIZE As Integer = 50       ' Maximum array size
    Dim many As Integer = 0             ' Actual size used.  (Number of employees.)

    '//////// Employee data.
    Dim id(MAXSIZE) As Integer           ' Array of ID numbers.
    '++++ Just ID for now; add more, later. ++++
    '...



    '//////// METHODS FOR FILE INPUT ////////
    Private Sub bAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bAdd.Click
        '////////  Get next employee input from form; store into array.
        '++++ Just ID for now; add more, later. ++++

        Dim nextid As Integer
        Dim nextln As String = ""
        Dim nextfn As String = ""
        Dim nextdep, nextcode As Integer
        Dim nextrate As Double

        Call getInputs(nextid, nextln, nextfn, nextdep, nextcode, nextrate)
        '@@@@   showit("bAdd:  nextid= " & Format(nextid))

        '//// Store the values into array(s).
        Call storeValues(nextid)

    End Sub
    Sub getInputs(ByRef nextid As Integer, _
            ByVal nextln As String, ByVal nextfn As String, _
            ByVal nextdep As Integer, ByVal nextcode As Integer, ByVal nextrate As Double)
        '//// Get input value(s) from the form.
        '++++ Just ID for now; add more, later. ++++
        '...
        '//// Get input value(s)
        nextid = Val(Me.tID.Text)

        '//// Also, clear the input(s).
        Me.tID.Text = ""
    End Sub
    Sub storeValues(ByVal nextid As Integer)
        '//////// Store the value(s) into the array(s).
        '++++ Just ID for now; add more, later. ++++
        '...
        '//// Check for room in array, bad values, etc. 
        '@@@@   showit("storeValues:  nextid= " & Format(nextid))
        If (many >= MAXSIZE) Then
            MsgBox("No more room in arrays:  ", many)
            Return
        ElseIf (nextid <= 0) Then               ' Error check(s)
            MsgBox("Bad ID ignored:  ", nextid)
            Return
        Else
            '//// Advance the index, for next array element.
            many += 1                       ' Next employee
            Dim n = many
            '//// Store the input value(s) into the array(s).
            id(n) = nextid
            '++++ Just ID for now; add more, later. ++++
            '...
        End If
    End Sub

    '///////// METHODS FOR FILE INPUT ////////
    Private Sub bRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bRead.Click
        '//// Input data from a file.
        Dim sr As IO.StreamReader
        sr = IO.File.OpenText(Me.tFilename.Text)    ' Get filename from textbox

        '@@@@   showit(Me.tFilename.Text & " was openned") '@@@
        '@@@@   showit("PEEK:  " & sr.Peek)

        While (sr.Peek <> -1)

            '//// read the next record into string "s".
            Dim s As String
            s = sr.ReadLine             ' Read record into s
            '@@@@   showit(s) '@@@

            '//// Extract values from s.
            Dim nextID As Integer
            Call getFields(s, nextID)

            '//// Store values into the array(s).
            Call storeValues(nextID)
        End While
    End Sub
    Sub getFields(ByVal s As String, ByRef nextid As Integer)
        '//// Decode the values from fields of the input string 
        '++++ Just ID for now; add more, later. ++++
        '...
        '//// Get input value(s)
        nextid = Val(s)
    End Sub



    '//////// OUTPUT METHODS ////////
    Sub clearout()
        '//// Clear output area
        Me.oListbox.Items.Clear()
    End Sub
    Sub showit(ByVal s As String)
        '//// Display a string
        Me.oListbox.Items.Add(s)
    End Sub
    Sub showit(ByVal s As String, ByVal x As Double)
        '//// Display a string and a value
        Me.oListbox.Items.Add(s & Format(x))
    End Sub
    Sub showit(ByVal s As String, ByVal x As Integer)
        '//// Display a string and a value
        Me.oListbox.Items.Add(s & Format(x))
    End Sub
    Sub showit(ByVal s As String, ByVal x As String)
        '//// Display a string and a value
        Me.oListbox.Items.Add(s & Format(x))
    End Sub

    '//////// OUTPUT THE ARRAY VALUES ////////
    Private Sub bReport_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bReport.Click
        '//////// Show all elements of array.
        Call clearout()
        Call showit("Number of elements in array:  ", many)

        ' OUTPUT:  Show each element
        Dim j As Integer = 0
        For j = 1 To many
            Call showemp(j)
        Next
    End Sub
    Sub showemp(ByVal j As Integer)
        '//// Display data for one employee.
        Dim s As String
        s = Format(id(j))
        Call showit(s)

        '++++ STUB.  Add more employee data.

    End Sub



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '//////// Clear the array(s).
        many = 0
    End Sub

    Private Sub bBig_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bBig.Click
        '//////// Find biggest value in the array.
        Dim k As Integer
        k = wherebig(id, many)
        showit(" The biggest value is at id(" & Format(k) & ")= ", id(k))
    End Sub
    Function wherebig(ByVal a() As Integer, ByVal m As Integer) As Integer
        '//// Return index of biggest in array.
        Dim w As Integer = 1        ' Start with w=1
        Dim j As Integer
        For j = 2 To m               ' Search array for anything bigger; save index
            If (a(j) > a(w)) Then
                w = j
            End If
        Next
        Return w
    End Function

    Private Sub bTiny_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bTiny.Click
        '//////// Find smallest value in the array.
        Dim k As Integer
        k = wheresmall(id, many)
        showit(" The smallest value is at id(" & Format(k) & ")= ", id(k))
    End Sub
    Function wheresmall(ByVal a() As Integer, ByVal m As Integer) As Integer
        '//// Return index of smallest in array.
        Dim w As Integer = 1        ' Start with w=1
        Dim j As Integer
        For j = 2 To m               ' Search array for anything smaller; save index
            If (a(j) < a(w)) Then
                w = j
            End If
        Next
        Return w
    End Function

    Private Sub bMatch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bMatch.Click
        '//// Find matching value in array
        Dim nextid As String = Me.tMatch.Text
        Dim k As Integer
        k = lookup(nextid, id, many)
        If (k > 0) Then
            showit(" The matching value is at id(" & Format(k) & ")= ", id(k))
        Else
            showit("No match for ", nextid)
        End If
    End Sub
    Function lookup(ByVal it As Integer, ByVal a() As Integer, ByVal m As Integer) As Integer
        '//// Return index of matching value.
        Dim w As Integer = -1        ' Start with w=1
        Dim j As Integer
        For j = 1 To m               ' Search array for match
            If (a(j) = it) Then
                w = j
            End If
        Next
        Return w
    End Function

    Private Sub bBinarySearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bBinarySearch.Click
        '////Binary search to find match
        Dim nextid As String = Me.tMatch.Text
        Dim k As Integer
        k = lookup(nextid, id, many)
        If (k > 0) Then
            showit(" The matching value is at id(" & Format(k) & ")= ", id(k))
        Else
            showit("No match for ", nextid)
        End If
    End Sub
    Function binsearch(ByVal it As Integer, ByVal a() As Integer, ByVal m As Integer) As Integer
        '//// Return index of matching value.
        Dim w As Integer = -1        ' Start with w=1
        Dim j As Integer
        '+++++++++++  CHANGE THIS TO BINARY SEARCH +++++

        Return w
    End Function

    Private Sub bSort_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bSort.Click
        '//// Sort the "id" array (ascending order)
        Call sortarray(id, many)
    End Sub
    Sub sortarray(ByRef a() As Integer, ByVal m As Integer)
        '//// Sort an array.
        Dim j, k As Integer
        For j = m To 2 Step -1      ' Go backwards, making array smaller & smaller
            k = wherebig(a, j)      ' Find the biggest.
            Call swap(a, j, k)      ' Move biggest to end
        Next
    End Sub
    Sub swap(ByVal a() As Integer, ByVal j As Integer, ByVal k As Integer)
        '//// Swap two elements of array.
        Dim tmp As Integer
        tmp = a(j)
        a(j) = a(k)
        a(k) = tmp
    End Sub

End Class