Day 1

.github/workflows/readme-stars.yml

@@ -4,6 +4,9 @@ on:
     # !Please set a different minute than 51 if you enable this!
     # schedule:
     #     - cron: "51 */6 * * *" # Every 6 hours
+    push:
+        branches:
+    	    - "master"
     workflow_dispatch:
 
 jobs:

data/examples/01-2.txt

@@ -0,0 +1,7 @@
+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen

data/examples/01.txt

@@ -0,0 +1,4 @@
+1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet

src/bin/01.rs

@@ -0,0 +1,76 @@
+advent_of_code::solution!(1);
+
+pub fn part_one(input: &str) -> Option<u32> {
+    Some(
+        input
+            .lines()
+            .filter_map(|line| {
+                let mut nums = line.chars().filter(|ch| ch.is_numeric());
+                let first = nums.next().and_then(|ch| ch.to_digit(10));
+                let last = nums.next_back().and_then(|ch| ch.to_digit(10)).or(first);
+                first.zip(last).map(|(a, b)| a * 10 + b)
+            })
+            .sum(),
+    )
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    let digit_strs = [
+        ("one", 1u32),
+        ("two", 2),
+        ("three", 3),
+        ("four", 4),
+        ("five", 5),
+        ("six", 6),
+        ("seven", 7),
+        ("eight", 8),
+        ("nine", 9),
+        ("1", 1),
+        ("2", 2),
+        ("3", 3),
+        ("4", 4),
+        ("5", 5),
+        ("6", 6),
+        ("7", 7),
+        ("8", 8),
+        ("9", 9),
+    ];
+    Some(
+        input
+            .to_ascii_lowercase()
+            .lines()
+            .filter_map(|line| {
+                let first = digit_strs
+                    .iter()
+                    .filter_map(|&(s, val)| line.find(s).map(|index| (index, val)))
+                    .min_by_key(|&(index, _)| index)
+                    .map(|(_, val)| val);
+                let last = digit_strs
+                    .iter()
+                    .filter_map(|&(s, val)| line.rfind(s).map(|index| (index, val)))
+                    .max_by_key(|&(index, _)| index)
+                    .map(|(_, val)| val);
+                first.zip(last).map(|(a, b)| a * 10 + b)
+            })
+            .sum(),
+    )
+}
+
+#[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(142));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file_part(
+            "examples", DAY, 2,
+        ));
+        assert_eq!(result, Some(281));
+    }
+}