4.3 Solutions

    1. for count : 1 .. 9
   for i : 1 .. count
   	put " "..
   end for
   put "*"
end for
    2. for decreasing i : 4 .. 1
   put i**2
end for 
  2. const PASSWORD := "Something Impossible to Guess"
var guess : string
var tries : int := 0

loop
   put "Enter password"
   get guess:*
   tries := tries + 1
   exit when tries = 3 or guess = PASSWORD
end loop

if guess = PASSWORD then
   put "Welcome to the system"
else
   put "ACCESS DENIED! Go away."
end if
  3.  
    % Assuming Only Valid Characters
    var num : int

loop
   put "Enter a positive integer less than 1000"
   get num
   exit when num > 0 and num < 1000
   put "That was an invalid input."
   if num <= 0 then
      put "You need a larger number."
   else
      put "You need a smaller number."
   end if
end loop 
    % Error Proof Version
    var num : int
var input : string
loop
   loop
      put "Enter a positive integer less than 1000"
      get input:*
      exit when strintok(input)
      put "Please enter a valid integer"
   end loop
   num := strint(input)
   exit when num > 0 and num < 1000
   put "That was an invalid input."
   if num <= 0 then
      put "You need a larger number."
   else
      put "You need a smaller number."
   end if
end loop