| -- The Computer Language Shootout |
| -- http://shootout.alioth.debian.org/ |
| -- contributed by Mike Pall |
| |
| local function ack(m, n) |
| if m == 0 then return n+1 end |
| if n == 0 then return ack(m-1, 1) end |
| return ack(m-1, (ack(m, n-1))) -- The parentheses are deliberate. |
| end |
| |
| local function fib(n) |
| if n < 2 then return 1 end |
| return fib(n-2) + fib(n-1) |
| end |
| |
| local function tak(x, y, z) |
| if y >= x then return z end |
| return tak(tak(x-1, y, z), tak(y-1, z, x), (tak(z-1, x, y))) |
| end |
| |
| local write, format = io.write, string.format |
| local n = tonumber(arg[1]) - 1 |
| write(format("Ack(3,%d): %d\n", n+1, ack(3, n+1))) |
| write(format("Fib(%.1f): %.1f\n", n+28.0, fib(n+28.0))) |
| write(format("Tak(%d,%d,%d): %d\n", 3*n, 2*n, n, tak(3*n, 2*n, n))) |
| write(format("Fib(3): %d\n", fib(3))) |
| write(format("Tak(3.0,2.0,1.0): %.1f\n", tak(3.0, 2.0, 1.0))) |
| |
