| // Copyright 2012 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use std::env; |
| |
| fn fib(n: i64) -> i64 { |
| if n < 2 { |
| return 1; |
| } else { |
| return fib(n - 1) + fib(n - 2); |
| } |
| } |
| |
| fn main() { |
| let args = env::args(); |
| let args = if env::var_os("RUST_BENCH").is_some() { |
| vec!("".to_string(), "40".to_string()) |
| } else if args.len() <= 1 { |
| vec!("".to_string(), "30".to_string()) |
| } else { |
| args.collect() |
| }; |
| let n = args[1].parse().unwrap(); |
| println!("{}\n", fib(n)); |
| } |