gistfile1.rs

use std::io;
use std::rand;

enum Ordering {
    Bigger,
    Smaller,
    Equal,
}

fn cmp(x: usize, y: usize) -> Ordering {
    if x > y {
        Ordering::Bigger
    } else if x == y {
        Ordering::Equal
    } else {
        Ordering::Smaller
    }
}

fn main() {
    println!("Type a number");
    let secret_number = (rand::random::<usize>() % 100) + 1; // secret_number: i32
    loop {
        let input = io::stdin().read_line().ok().expect("Failed to read line");
        let input_num: Option<usize> = input.trim().parse();
        let num = match input_num {
            Some(num) => num,
            None      => {
                println!("Please input a number!");
                continue;
            }
        };

        let result = match cmp(secret_number, num) {
            Ordering::Bigger => "Bigger",
            Ordering::Smaller => "Smaller",
            Ordering::Equal => {
                println!("You win!");
                return;
            }
        };
        println!("{}", result);
    }
}