feat: solve day 1

data/examples/01.txt

@@ -0,0 +1,11 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82
+

src/bin/01.rs

@@ -0,0 +1,70 @@
+advent_of_code::solution!(1);
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let mut rot = 50;
+    let mut num = 0;
+    input.lines().for_each(|l| {
+        let mut mult = 1;
+        if l.contains("L") {
+            mult = -1;
+        }
+        let mut chars = l.chars();
+        chars.next();
+        let curr = chars.as_str().parse().unwrap_or(0);
+        rot += mult * curr;
+        while rot >= 100 {
+            rot -= 100;
+        }
+        while rot < 0 {
+            rot += 100;
+        }
+        if rot == 0 {
+            num += 1;
+        }
+    });
+    Some(num)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    let mut new_lines = vec![];
+    input.lines().for_each(|l| {
+        let mut chars = l.chars();
+        let start = chars.next();
+        let curr = chars.as_str().parse().unwrap_or(0);
+        if let Some(start_char) = start {
+            for _ in 0..curr {
+                new_lines.push(format!("{start_char}1"));
+            }
+        }
+    });
+    part_one(&new_lines.join("\n"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(3));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let mut result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(6));
+
+        result = part_two("L1000");
+        assert_eq!(result, Some(10));
+
+        result = part_two("L50");
+        assert_eq!(result, Some(1));
+        result = part_two("R50\nR50");
+        assert_eq!(result, Some(1));
+        result = part_two("R50\nL50");
+        assert_eq!(result, Some(1));
+        result = part_two("L50\nL50");
+        assert_eq!(result, Some(1));
+    }
+}