Working great ! :D

src/lib.rs

@@ -1,2 +1,4 @@
+extern crate core;
+
 pub mod prob1;
 pub mod prob2;

src/main.rs

@@ -5,6 +5,6 @@ fn main() {
     let file_path = args
         .get(1)
         .expect("Please provide an argument on command-line.");
-    let max = prob2::solve_part1(file_path);
+    let max = prob2::solve_part2(file_path);
     println!("{max}");
 }

src/prob2/mod.rs

@@ -5,6 +5,7 @@ pub enum Play {
     Scissors,
 }
 
+#[derive(Copy, Clone)]
 enum ResultPlay {
     Win,
     Draw,
@@ -97,6 +98,41 @@ pub fn round_score(play: char, counter_play: char) -> i32 {
     }
 }
 
+fn choose_answer(strat: &ResultPlay, input: Play) -> Play {
+    use Play::*;
+    use ResultPlay::*;
+    match strat {
+        Loss => match input {
+            Rock => Scissors,
+            Paper => Rock,
+            Scissors => Paper,
+        },
+        Draw => input,
+        Win => match input {
+            Rock => Paper,
+            Paper => Scissors,
+            Scissors => Rock,
+        },
+    }
+}
+
+fn getting_score(game_output: &ResultPlay, play: Play) -> i32 {
+    let game: i32 = (*game_output).into();
+    let play_result: i32 = play.into();
+    game + play_result
+}
+
+pub fn second_strat(play: char, strat: char) -> i32 {
+    let coup = Play::from(play);
+    let response = match strat {
+        'X' => ResultPlay::Loss,
+        'Y' => ResultPlay::Draw,
+        'Z' => ResultPlay::Win,
+        other => panic!("Wrong letter {other}"),
+    };
+    getting_score(&response, choose_answer(&response, coup))
+}
+
 pub fn solve_part1(file_path: &str) -> i32 {
     let contents =
         std::fs::read_to_string(file_path).expect("Please provide a text file as an argument.");
@@ -113,3 +149,20 @@ pub fn solve_part1(file_path: &str) -> i32 {
         .iter()
         .sum()
 }
+
+pub fn solve_part2(file_path: &str) -> i32 {
+    let contents =
+        std::fs::read_to_string(file_path).expect("Please provide a text file as an argument.");
+    let lines: Vec<&str> = contents.split('\n').collect();
+    lines
+        .iter()
+        .map(|line| {
+            let mut line_iter = line.chars();
+            let first: char = line_iter.next().unwrap_or('R');
+            let last: char = line_iter.last().unwrap_or('R');
+            second_strat(first, last)
+        })
+        .collect::<Vec<i32>>()
+        .iter()
+        .sum()
+}