#
# this was our guesser function from class
#
guesser <- function(hidden,verbose=T)
{
  g <- -1
  i <- 0
  repeat {
    g <- sample(1:100,1)
    i <- i+1
    if (verbose == T) {cat("My guess now is",g,"\n")}
    if (g == hidden) break
  }
  if (verbose == T) {
    cat("I got it! Your # was", g, ".")
    cat("\nIt took",i,"guesses.\n") 
  }
  return(i)
}

"
Below is a function that runs ONE trial of
the Monty Hall three-curtain game from the
show 'Let's Make a Deal'

Run this with the command
>  MH()
"
MH <- function()
{  
  # get the winning curtain into prize
  prize = sample(1:3,1)
  cat("Aside: [[ The prize is behind",prize,"]]\n")
  
  # get the user's curtain into user
  cat("Welcome! Choose a curtain: 1, 2, or 3:\n")
  user <- scan(n=1)  # this is how to get one input
  cat("OK, you chose curtain", user,"\n") 
  
  # get the garbage curtain into g
  g = 6-user-prize # trick to getting garbage curtain
  # that trick needs to be fixed if prize == user
  if (prize == user) {
    g = prize+1
    # if g gets too big, wrap around
    if (g > 3) { g = 1 } 
  }
  
  # chatter from Monty Hall
  cat("Aha! It's good you didn't choose curtain",g,"\n")
  cat("Because that had a consolation prize...\n")
  cat("Do you want to switch or stay?\n")
  cat("You may type \"switch\" or \"stay\":\n")
  sors <- scan(what=" ",n=1) # this takes _text_ input
  
  # Let's find the other curtain
  switch_curtain = 6-prize-g
  cat("You choose to",sors,".\n")  
  if (sors == "stay") {
    cat("Your curtain is still", user, "\n")
  } else {
    cat("Your curtain is now", switch_curtain,"\n")
  }
  
  # Announce the prize curtain
  cat("The prize was behind curtain", prize, "... ")
  
  # Now, we decide whether it's a win or loss
  # Losing cases
  if ((sors == "switch" & user==prize) |  # or
        (sors == "stay" & user!=prize))
  {
    cat("You LOSE!\n")
    return(0)
  }
  # winning cases
  else 
  {
    cat("You WIN!\n")
    return(1)
  }
}