Day 2 done.

1 files changed, 70 insertions, 0 deletions

diff --git a/2024/Rust/src/day2.rs b/2024/Rust/src/day2.rs
new file mode 100644
index 0000000..22dd5dd
--- /dev/null
+++ b/2024/Rust/src/day2.rs
@@ -0,0 +1,70 @@
+type Reports = Vec<Vec<i32>>;
+
+fn parse_input(data: &str) -> Reports {
+    data.lines()
+        .map(|line| {
+            line.split(" ")
+                .map(|x| x.parse::<i32>().unwrap())
+                .collect::<Vec<i32>>()
+        })
+        .collect()
+}
+
+fn is_safe_recursive(report: &[i32]) -> bool {
+    match report {
+        [] => false,
+        [_] => false,
+        [a, b] => (1..=3).contains(&(a - b).abs()),
+        [a, b, rest @ ..] => (1..=3).contains(&(a - b).abs()) && is_safe_recursive(rest),
+    }
+}
+
+fn is_safe(report: &Vec<i32>) -> bool {
+    let increasing = report[0] < report[1];
+    for i in 0..report.len() - 1 {
+        if increasing {
+            let diff = report[i + 1] - report[i];
+            if report[i] >= report[i + 1] || diff > 3 || diff < 1 {
+                return false;
+            }
+        } else {
+            let diff = report[i] - report[i + 1];
+            if report[i] <= report[i + 1] || diff > 3 || diff < 1 {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+fn solve_part_one(data: &str) -> usize {
+    let reports = parse_input(data);
+    reports.iter().filter(|&report| is_safe(report)).count()
+}
+
+fn solve_part_two(data: &str) -> usize {
+    let reports = parse_input(data);
+    let mut cnt: usize = 0;
+    reports
+        .iter()
+        .filter(|&report| !is_safe(report))
+        .for_each(|report| {
+            for i in 0..report.len() {
+                let mut report_copy = report.clone();
+                report_copy.remove(i);
+                if is_safe(&report_copy) {
+                    cnt += 1;
+                    break;
+                }
+            }
+        });
+    cnt + reports.iter().filter(|&report| is_safe(report)).count()
+}
+fn main() {
+    let test_1 = include_str!("../input/day_2.test");
+    let prod = include_str!("../input/day_2.prod");
+    println!("part_1 test: {:?}", solve_part_one(test_1));
+    println!("part_1 prod {:?}", solve_part_one(prod));
+    println!("part_2 test: {:?}", solve_part_two(test_1));
+    println!("part_2 prod {:?}", solve_part_two(prod));
+}