rust/src/test/bench/shootout-ackermann.rs

26 lines
525 B
Rust

extern mod std;
fn ack(m: int, n: int) -> int {
if m == 0 {
return n + 1
} else {
if n == 0 {
return ack(m - 1, 1);
} else {
return ack(m - 1, ack(m, n - 1));
}
}
}
fn main(args: ~[~str]) {
let args = if os::getenv(~"RUST_BENCH").is_some() {
~[~"", ~"12"]
} else if args.len() <= 1u {
~[~"", ~"8"]
} else {
args
};
let n = int::from_str(args[1]).get();
io::println(fmt!("Ack(3,%d): %d\n", n, ack(3, n)));
}