reverse.lua

-- Reverse game in Lua 5.1
-- See http://e-scribe.com/news/193 for background
-- My first stab at Lua coding

math.randomseed(os.time())
math.random()

input = {1,2,3,4,5,6,7,8,9}
numbers = {}
for i=1,9 do
  table.insert(numbers, table.remove(input, math.random(#input)))
end

function flip(sequence, howmany)
  flipped = {}
  for i=1,#sequence do
    if i<=howmany then 
      flipped[i] = sequence[howmany+1-i]
    else 
      flipped[i] = sequence[i] 
    end
  end
  return flipped
end

function disordered(sequence)
  for i=2,#sequence do
    if sequence[i-1] > sequence[i] then 
      return true 
    end
  end
  return false
end

count = 0
while disordered(numbers) do
  io.write(table.concat(numbers, " ").."\nHow many to flip? ")
  howmany = tonumber(io.read())
  numbers = flip(numbers, howmany)
  count = count + 1
end

io.write("Done! That took you "..count.." steps.\n")