add: files so far

d/d2p1.rs

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+use advent_of_code_2024::{make_main, SResult};
+
+make_main!();
+
+// CODE
+
+#[derive(PartialEq)]
+enum Direction {
+    Up,
+    Down,
+}
+
+impl Direction {
+    fn from(a: usize, b: usize) -> Self {
+        if a > b {
+            Direction::Down
+        } else {
+            Direction::Up
+        }
+    }
+}
+
+fn solve(lines: Vec<String>) -> SResult<usize> {
+    let mut failed = 0;
+    for line in lines.iter() {
+        let reports: Vec<usize> = line.split_whitespace().map(|v| v.parse::<usize>().unwrap()).collect();
+        let mut i = 0;
+        let direction = Direction::from(reports[0], reports[1]);
+        while i + 1 < reports.len() {
+            let delta = reports[i].abs_diff(reports[i+1]);
+            if delta < 1 || delta > 3 {
+                failed += 1;
+                break;
+            }
+            if direction != Direction::from(reports[i], reports[i+1]) {
+                failed += 1;
+                break;
+            }
+            i += 1;
+        }
+    }
+    Ok(lines.len() - failed)
+}
+
+// CODE
+
+#[cfg(test)]
+mod tests {
+    use advent_of_code_2024::input;
+
+    use super::*;
+    #[test]
+    fn sample_input() {
+        let strings: Vec<String> = input!("d2p1.txt");
+        let got = solve(strings).unwrap();
+        assert_eq!(got, 2);
+    }
+}