Adding regex crate and day3 part 1 solution.

2024/rust/src/day3.rs

@@ -0,0 +1,27 @@
+use crate::Solution;
+use std::fs;
+use std::process;
+use regex::Regex;
+
+pub fn run_day_3() -> Solution {
+    
+    let file = fs::read_to_string("./inputs/day3.txt").expect("Unable to parse file");
+    let re = Regex::new("mul\\((\\d{1,3}),(\\d{1,3})\\)").unwrap();
+    let mut part1_sum = 0;
+    for mul in re.captures_iter(&file) {
+        // Multiply the second and the third matches.
+        let num1: &u32 = &mul[1].parse().expect("Conversion failed");
+        let num2: &u32 = &mul[2].parse().expect("Conversion failed");
+        let total = num1 * num2;
+        part1_sum += total;
+    }
+
+    
+    let solution = Solution {
+        day: 3,
+        answer_1: part1_sum.to_string(),
+        answer_2: "Not sure".to_string(),
+    };
+    
+    solution
+}

2024/rust/src/main.rs

@@ -4,6 +4,7 @@
 use tabled::{Table, Tabled};
 pub mod day1;
 pub mod day2;
+pub mod day3;
 
 #[derive(Tabled)]
 pub struct Solution {
@@ -31,8 +32,10 @@ fn main() {
     let mut rows = Vec::new();
     let day1 = day1::run_day_1();
     let day2 = day2::run_day_2();
+    let day3 = day3::run_day_3();
     rows.push(day1);
     rows.push(day2);
+    rows.push(day3);
 
     let table = Table::new(rows);