day 2, rust

02/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc2024-02"
+version = "0.1.0"

02/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "aoc2024-02"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

02/src/main.rs

@@ -0,0 +1,65 @@
+fn is_safe(items: &Vec<i32>) -> bool {
+    let deltas: Vec<_> = items
+        .iter()
+        .scan(None, |p, s| match p.clone() {
+            None => {
+                *p = Some(*s);
+                Some(None)
+            }
+            Some(v) => {
+                *p = Some(*s);
+                Some(Some(*s - v))
+            }
+        })
+        .flatten()
+        .collect();
+    if deltas.iter().all(|x| *x >= 1 && *x <= 3) || deltas.iter().all(|x| *x >= -3 && *x <= -1) {
+        true
+    } else {
+        false
+    }
+}
+
+fn main() {
+    let raw = std::fs::read_to_string("input.txt").expect("Couldn't read input");
+    let first: i32 = raw
+        .split("\n")
+        .filter(|line| !line.is_empty())
+        .map(|line| {
+            let items = line
+                .split(" ")
+                .map(|x| x.parse())
+                .collect::<Result<Vec<i32>, _>>()
+                .unwrap();
+            if is_safe(&items) {
+                1
+            } else {
+                0
+            }
+        })
+        .sum();
+    println!("{}", first);
+    let second: i32 = raw
+        .split("\n")
+        .filter(|line| !line.is_empty())
+        .map(|line| {
+            let items = line
+                .split(" ")
+                .map(|x| x.parse())
+                .collect::<Result<Vec<i32>, _>>()
+                .unwrap();
+            if is_safe(&items) {
+                1
+            } else if (0..items.len()).any(|i| {
+                let mut items = items.clone();
+                items.remove(i);
+                is_safe(&items)
+            }) {
+                1
+            } else {
+                0
+            }
+        })
+        .sum();
+    println!("{}", second);
+}