'This file is named missquare.vb
'Generates random U[0, 1) variates by the MidSquare method (not very good, but good practice using loops)
Imports System

Public Module LoopIntro
   Sub Main()

	'seed is a four-digit starting value	(1000 <= seed <= 9999)
	'n is the number of random variates to generate (n > 0)
	Dim n, seed As Integer		'read from user
	Dim i, sqr, mid As Integer

	System.Console.Writeline("This program was written by Kevin Jones.  All rights reserved...")
	System.Console.Writeline()

	System.Console.Write("How many random numbers do you require? ")
	n = System.Console.Readline()
	System.Console.Write("Please enter the four-digit seed value (between 1000 and 9999): ")
	seed = System.Console.Readline()

	while not(seed >= 1000 and seed <= 9999)
		System.Console.Writeline("Sorry, the seed you entered is invalid.  Try again.")
		System.Console.Write("Please enter the four-digit seed value (between 1000 and 9999): ")
		seed = System.Console.Readline()
	end while

	'now seed is good

	mid = seed
	for i = 1 to n
		sqr = mid ^ 2		'square the four-digit number
		sqr = sqr \ 100		'lose the right-most 2 digits
		mid = sqr Mod 10000	'keep the new right-most 4-digits (chooses "middle 4" of sqr)
		System.Console.Writeline(mid / 10000.0)
	next i

	System.Console.Writeline("Thanks...Bye!")

   End Sub
End Module