solution: day10

src/bin/10.rs

@@ -0,0 +1,54 @@
+fn process(s: &str) -> String {
+    let mut new_s = String::new();
+    let mut count = 0;
+    let mut current = s.chars().next().unwrap();
+
+    for c in s.chars() {
+        if c == current {
+            count += 1;
+        } else {
+            new_s.push_str(&count.to_string());
+            new_s.push(current);
+            current = c;
+            count = 1
+        }
+    }
+
+    new_s.push_str(&count.to_string());
+    new_s.push(current);
+    new_s
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let mut res = input.to_string();
+    for _ in 0..40 {
+        res = process(&res);
+    }
+    Some(res.len() as u32)
+}
+pub fn part_two(input: &str) -> Option<u32> {
+    let mut res = input.to_string();
+    for _ in 0..50 {
+        res = process(&res);
+    }
+    Some(res.len() as u32)
+}
+fn main() {
+    let input = &aoc::read_file("inputs", 10);
+    aoc::solve!(1, part_one, input);
+    aoc::solve!(2, part_two, input);
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_part_one() {
+        let input = aoc::read_file("test_inputs", 10);
+        assert_eq!(part_one(&input), Some(124496));
+    }
+    #[test]
+    fn test_part_two() {
+        let input = aoc::read_file("test_inputs", 10);
+        assert_eq!(part_two(&input), Some(1766402));
+    }
+}