day3 part1

src/day3.rs

@@ -0,0 +1,44 @@
+#[aoc(day3, part1)]
+pub fn part1(input: &str) -> u32 {
+    input.split("\n").map(|line| get_joltage(line)).sum()
+}
+
+fn get_joltage(line: &str) -> u32 {
+    let len = line.len();
+    let (revpos_1, val_1) = line[..(len - 1)]
+        .chars()
+        .rev()
+        .enumerate()
+        .max_by(|x, y| x.1.cmp(&y.1))
+        .unwrap();
+
+    let val_2 = line[(len - 1 - revpos_1)..].chars().max().unwrap();
+    let result = val_1.to_digit(10).unwrap() * 10 + val_2.to_digit(10).unwrap();
+
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1_1() {
+        let input = String::from(
+            "987654321111111
+811111111111119
+234234234234278
+818181911112111",
+        );
+        assert_eq!(part1(&input), 357)
+    }
+    #[test]
+    fn test_part1_2() {
+        let input = String::from(
+            "9891111111111111111
+111111111111111
+818181911112111",
+        );
+        assert_eq!(part1(&input), 99 + 11 + 92)
+    }
+}