Data commit

Task/Penneys-game/Rust/penneys-game.rust

@@ -0,0 +1,105 @@
+extern crate rand;
+
+use std::io::{stdin, stdout, Write};
+use std::thread;
+use std::time::Duration;
+
+use rand::Rng;
+
+fn toss_coin<R: Rng>(rng: &mut R, print: bool) -> char {
+    let c = if rng.gen() { 'H' } else { 'T' };
+    if print {
+        print!("{}", c);
+        stdout().flush().expect("Could not flush stdout");
+    }
+    c
+}
+
+fn gen_sequence<R: Rng>(rng: &mut R, seed: Option<&str>) -> String {
+    let mut seq = String::new();
+    match seed {
+        Some(s) => {
+            let mut iter = s.chars();
+            let c0 = iter.next().unwrap();
+            let next = if c0 == 'H' { 'T' } else { 'H' };
+            seq.push(next);
+            seq.push(c0);
+            seq.push(iter.next().unwrap());
+        }
+        None => {
+            for _ in 0..3 {
+                seq.push(toss_coin(rng, false))
+            }
+        }
+    }
+    seq
+}
+
+fn read_sequence(used_seq: Option<&str>) -> String {
+    let mut seq = String::new();
+    loop {
+        seq.clear();
+        println!("Please, enter sequence of 3 coins: H (heads) or T (tails): ");
+        stdin().read_line(&mut seq).expect("failed to read line");
+        seq = seq.trim().to_uppercase();
+        // do the cheapest test first
+        if seq.len() == 3
+            && seq.chars().all(|c| c == 'H' || c == 'T')
+            && seq != used_seq.unwrap_or("")
+        {
+            return seq;
+        }
+
+        println!("Please enter correct sequence!");
+    }
+}
+
+fn main() {
+    let mut rng = rand::thread_rng();
+
+    println!("--Penney's game--");
+    loop {
+        let useq: String;
+        let aiseq: String;
+        if rng.gen::<bool>() {
+            println!("You choose first!");
+            useq = read_sequence(None);
+            println!("Your sequence: {}", useq);
+            aiseq = gen_sequence(&mut rng, Some(&useq));
+            println!("My sequence: {}", aiseq);
+        } else {
+            println!("I choose first!");
+            aiseq = gen_sequence(&mut rng, None);
+            println!("My sequence: {}", aiseq);
+            useq = read_sequence(Some(&aiseq));
+            println!("Your sequence: {}", useq);
+        }
+        println!("Tossing coins...");
+        let mut coins = String::new();
+        for _ in 0..2 {
+            // toss first 2 coins
+            coins.push(toss_coin(&mut rng, true));
+            thread::sleep(Duration::from_millis(500));
+        }
+        loop {
+            coins.push(toss_coin(&mut rng, true));
+            thread::sleep(Duration::from_millis(500));
+            if coins.contains(&useq) {
+                println!("\nYou win!");
+                break;
+            }
+            if coins.contains(&aiseq) {
+                println!("\nI win!");
+                break;
+            }
+        }
+
+        println!(" Play again? 'Y' to play, 'Q' to exit.");
+        let mut input = String::new();
+        stdin().read_line(&mut input).expect("failed to read line");
+        match input.trim_start().chars().next().unwrap() {
+            'Y' | 'y' => continue,
+            _ => break,
+        }
+    }
+}