recursive.groovy

/*
 * The Computer Language Benchmarks Game
 * http://shootout.alioth.debian.org/
 *
 * contributed by Anthony Borla
 * modified by Isaac Gouy
 */

def ack(x, y) {
    if (x == 0) return y + 1
    if (y == 0) return ack(x - 1, 1)
    return ack(x - 1, ack(x, y - 1))
}

def fib(int n) {
    if (n < 2) return 1
    return fib(n - 2) + fib(n - 1)
}

def fib(double n) {
    if (n < 2.0D) return 1.0D
    return fib(n - 2.0D) + fib(n - 1.0D)
}

def tak(int x, int y, int z) {
    if (y < x) return tak(tak(x - 1, y, z), tak(y - 1, z, x), tak(z - 1, x, y))
    return z
}

def tak(double x, double y, double z) {
    if (y < x) return tak(tak(x - 1.0D, y, z), tak(y - 1.0D, z, x), tak(z - 1.0D, x, y))
    return z
}

def n = Integer.parseInt(args[0])

printf("Ack(3,%d): %d\n", n, ack(3, n))
printf("Fib(%.1f): %.1f\n", 27.0D + n, fib(27.0D + n))
n -= 1
printf("Tak(%d,%d,%d): %d\n", n * 3, n * 2, n, tak(n * 3, n * 2, n))
printf("Fib(3): %d\n", fib(3))
printf("Tak(3.0,2.0,1.0): %.1f\n", tak(3.0D, 2.0D, 1.0D))