completed day 3, ready for day 4.

Cargo.toml

@@ -14,5 +14,13 @@ path="src/template/solve.rs"
 name="day01"
 path="src/day01/solve.rs"
 
+[[bin]]
+name="day02"
+path="src/day02/solve.rs"
+
+[[bin]]
+name="day03"
+path="src/day03/solve.rs"
+
 [dependencies]
 regex="1"

src/day02/part1.rs

@@ -0,0 +1,63 @@
+use crate::utilities::*;
+pub fn part1(input: &str) -> usize {
+    parse(input).iter().map(calc_score).sum()
+}
+
+pub fn parse(input: &str) -> Vec<Strategy> {
+    input
+        .lines()
+        .map(|line| {
+            let elf = match line.as_bytes()[0] {
+                b'A' => Play::Rock,
+                b'B' => Play::Paper,
+                b'C' => Play::Scissors,
+                _ => panic!("your opponent not playing defined strategy!"),
+            };
+            let you = match line.as_bytes()[2] {
+                b'X' => Play::Rock,
+                b'Y' => Play::Paper,
+                b'Z' => Play::Scissors,
+                _ => panic!("you are not playing defined strategy!"),
+            };
+            Strategy { elf, you }
+        })
+        .collect()
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() {
+        let input = "A Y
+B X
+C Z";
+        assert_eq!(part1(input), 15);
+    }
+
+    #[test]
+    fn test_parse() {
+        let input = "A Y
+B X
+C Z";
+        assert_eq!(
+            parse(input),
+            vec![
+                Strategy {
+                    elf: Play::Rock,
+                    you: Play::Paper
+                },
+                Strategy {
+                    elf: Play::Paper,
+                    you: Play::Rock
+                },
+                Strategy {
+                    elf: Play::Scissors,
+                    you: Play::Scissors
+                }
+            ]
+        );
+    }
+}

src/day02/part2.rs

@@ -0,0 +1,87 @@
+use crate::utilities::*;
+
+pub enum GameResult {
+    Win,
+    Loss,
+    Draw,
+}
+
+pub struct ResultStrategy {
+    pub elf: Play,
+    pub you: GameResult,
+}
+
+pub fn part2(input: &str) -> usize {
+    parse(input)
+        .iter()
+        .map(gen_strategy)
+        .map(|strat| calc_score(&strat))
+        .sum()
+}
+
+fn gen_strategy(input: &ResultStrategy) -> Strategy {
+    match input.you {
+        GameResult::Win => Strategy {
+            elf: input.elf,
+            you: gen_win(input.elf),
+        },
+        GameResult::Draw => Strategy {
+            elf: input.elf,
+            you: input.elf,
+        },
+        GameResult::Loss => Strategy {
+            elf: input.elf,
+            you: gen_loss(input.elf),
+        },
+    }
+}
+
+fn gen_win(opponent: Play) -> Play {
+    match opponent {
+        Play::Rock => Play::Paper,
+        Play::Paper => Play::Scissors,
+        Play::Scissors => Play::Rock,
+    }
+}
+
+fn gen_loss(opponent: Play) -> Play {
+    match opponent {
+        Play::Rock => Play::Scissors,
+        Play::Paper => Play::Rock,
+        Play::Scissors => Play::Paper,
+    }
+}
+
+pub fn parse(input: &str) -> Vec<ResultStrategy> {
+    input
+        .lines()
+        .map(|line| {
+            let elf = match line.as_bytes()[0] {
+                b'A' => Play::Rock,
+                b'B' => Play::Paper,
+                b'C' => Play::Scissors,
+                _ => panic!("your opponent not playing defined strategy!"),
+            };
+            let you = match line.as_bytes()[2] {
+                b'X' => GameResult::Loss,
+                b'Y' => GameResult::Draw,
+                b'Z' => GameResult::Win,
+                _ => panic!("you are not playing defined strategy!"),
+            };
+            ResultStrategy { elf, you }
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part2() {
+        let input = "A Y
+B X
+C Z";
+        assert_eq!(part2(input), 12);
+    }
+}

src/day02/solve.rs

@@ -0,0 +1,13 @@
+mod part1;
+mod part2;
+mod utilities;
+
+fn main() {
+    let _input = include_str!("./input.txt");
+
+    println!("Part One");
+    println!("Result: {}", part1::part1(_input));
+
+    println!("Part Two");
+    println!("Result: {}", part2::part2(_input));
+}

src/day02/utilities.rs

@@ -0,0 +1,40 @@
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Play {
+    Rock = 1,
+    Paper = 2,
+    Scissors = 3,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Strategy {
+    pub elf: Play,
+    pub you: Play,
+}
+
+pub fn calc_score(input: &Strategy) -> usize{
+    //play enum has value corresponding to its score.
+    let mut score = input.you as usize;
+    //an enum wins if (you-elf)%3 = 1, looses if it = 2
+    let gamestatus = (input.you as i8 - input.elf as i8).rem_euclid(3);
+    match gamestatus {
+        1 => score+=6,
+        2 => (),
+        0 => score += 3,
+        _ => panic!("gamestatus was {}!, you were {}, elf was {}", gamestatus, input.you as i8, input.elf as i8)
+    }
+    score
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_calc_score() {
+            let input = Strategy {
+                    elf: Play::Scissors,
+                    you: Play::Scissors
+                };
+        assert_eq!(calc_score(&input), 6);
+    }
+}

src/day03/part1.rs

@@ -0,0 +1,15 @@
+use crate::utilities::*;
+
+pub fn part1() -> usize {
+    0
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() {
+        assert_eq!(part1(), 0);
+    }
+}

src/day03/part2.rs

@@ -0,0 +1,15 @@
+use crate::utilities::*;
+
+pub fn part2() -> usize {
+    0
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part2() {
+        assert_eq!(part2(), 0);
+    }
+}

src/day03/solve.rs

@@ -0,0 +1,14 @@
+mod part1;
+mod part2;
+mod utilities;
+
+fn main() {
+    let _input = include_str!("./input.txt");
+    let _structured_input = utilities::parse(_input);
+
+    println!("Part One");
+    println!("Result: {}", part1::part1());
+
+    println!("Part Two");
+    println!("Result: {}", part2::part2());
+}

src/template/part1.rs

@@ -1,3 +1,5 @@
+use crate::utilities::*;
+
 pub fn part1() -> usize {
     0
 }

src/template/part2.rs

@@ -1,3 +1,5 @@
+use crate::utilities::*;
+
 pub fn part2() -> usize {
     0
 }

src/template/solve.rs

@@ -1,10 +1,10 @@
 mod part1;
 mod part2;
-mod parse;
+mod utilities;
 
 fn main() {
     let _input = include_str!("./input.txt");
-    let _structured_input = parse::parse(_input);
+    let _structured_input = utilities::parse(_input);
 
     println!("Part One");
     println!("Result: {}", part1::part1());

src/template/utilities.rs

@@ -0,0 +1,17 @@
+pub fn parse(input: &str) -> usize {
+    println!("{}", input);
+    0
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse() {
+        let input =
+"test"
+;
+        assert_eq!(parse(input), 0);
+    }
+}