Solve Day 2 Part 1

Author: destinationunknown

data/examples/02.txt

@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9

src/bin/02.rs

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+advent_of_code::solution!(2);
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let reports: Vec<Vec<i32>> = input
+        .lines()
+        .filter_map(|line| {
+            Some(
+                line.split_whitespace()
+                    .filter_map(|x| x.parse::<i32>().ok())
+                    .collect::<Vec<i32>>(),
+            )
+        })
+        .collect();
+
+    let num_safe: i32 = reports
+        .iter()
+        .filter(|report| {
+            report.windows(2).all(|w| (1..=3).contains(&(w[1] - w[0])))
+                || report.windows(2).all(|w| (1..=3).contains(&(w[0] - w[1])))
+        })
+        .count() as i32;
+
+    Some(num_safe as u32)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    None
+}
+
+#[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(2));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}