Almost done haha

src/lib.rs

@@ -1,4 +1,3 @@
-extern crate core;
-
 pub mod prob1;
-pub mod prob2;
+pub mod prob2;
+pub mod prob3;

src/main.rs

@@ -1,4 +1,4 @@
-use advent_of_code::{prob1, prob2};
+use advent_of_code::{prob1, prob2, prob3};
 
 fn main() {
     {
@@ -13,4 +13,9 @@ fn main() {
         let max_part2 = prob2::solve_part2(file_path);
         println!("Solution for problem 2 part 1: {max_part1}\nSolution for problem 2 part 2: {max_part2}");
     }
+    {
+        let file_path = "prob3_part1.txt";
+        let max_part1 = prob3::solve_part1(file_path);
+        println!("{max_part1}");
+    }
 }

src/prob3/mod.rs

@@ -0,0 +1,19 @@
+use std::collections::HashSet;
+
+pub fn solve_part1(file_path: &str) -> i32 {
+    let binding =
+        std::fs::read_to_string(file_path).expect("Please provide a text file as an argument.");
+    let content = binding
+        .lines()
+        .collect::<Vec<&str>>()
+        .iter()
+        .map(|item: &&str| {
+            let (first, last) = item.split_at(item.len() / 2);
+            let second = last.chars().collect::<HashSet<char>>();
+            let intersection = first.chars().collect::<HashSet<char>>();
+            *intersection.intersection(&second).next().unwrap()
+        })
+        .collect::<Vec<char>>();
+
+    0
+}