Nim game: Difference between revisions

</pre>

=={{header|Rust}}==

<lang rust>use std::io;

fn main() {

let mut tokens = 12;

println!("Nim game");

println!("Starting with {} tokens.", tokens);

println!("");

loop {

tokens = p_turn(&tokens);

print_remaining(&tokens);

tokens = c_turn(&tokens);

print_remaining(&tokens);

if tokens == 0 {

println!("Computer wins!");

break;

}

}

}

fn p_turn(tokens: &i32) -> i32 {

loop { //try until we get a good number

println!("How many tokens would you like to take?");

let mut take = String::new();

io::stdin().read_line(&mut take)

.expect("Sorry, I didn't understand that.");

let take: i32 = match take.trim().parse() {

Ok(num) => num,

Err(_) => {

println!("Invalid input");

println!("");

continue;

}

};

if take > 3 || take < 1 {

println!("Take must be between 1 and 3.");

println!("");

continue;

}

return tokens - take;

}

}

fn c_turn(tokens: &i32) -> i32 {

let take = tokens % 4;

println!("Computer takes {} tokens.", take);

return tokens - take;

}

fn print_remaining(tokens: &i32) {

println!("{} tokens remaining.", tokens);

println!("");

}

</lang>

{{out}}

sample game:

<pre>

Nim game

Starting with 12 tokens.

How many tokens would you like to take?

foo

Invalid input

How many tokens would you like to take?

3

9 tokens remaining.

Computer takes 1 tokens.

8 tokens remaining.

How many tokens would you like to take?

5

Take must be between 1 and 3.

How many tokens would you like to take?

2

6 tokens remaining.

Computer takes 2 tokens.

4 tokens remaining.

How many tokens would you like to take?

1

3 tokens remaining.

Computer takes 3 tokens.

0 tokens remaining.

Computer wins!