✨ Day 2 (part 1, part 2 working in tests)

README.md

@@ -4,7 +4,7 @@
 [![Language: Rust](https://img.shields.io/badge/Language-Rust-orange.svg?style=flat-square)](https://en.wikipedia.org/wiki/Rust_(programming_language))
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg?style=flat-square)](https://mit-license.org/)
 ![Days completed](https://img.shields.io/badge/Days%20completed-1-red?style=flat-square)
-![Stars](https://img.shields.io/badge/Stars-2-yellow?style=flat-square)
+![Stars](https://img.shields.io/badge/Stars-3-yellow?style=flat-square)
 
 > ⚠️ This README is copied from my previous years solution. It is not fully adopted to 2024 yet.
 

src/days/d02.rs

@@ -2,31 +2,118 @@ use super::{Answer, Day, DayImpl};
 
 const CURRENT_DAY: u8 = 2;
 
-type Data = Vec<u64>;
+pub enum Direction {
+    Increasing,
+    Decreasing,
+}
+
+#[derive(Clone, Debug)]
+pub struct Report(Vec<i8>);
+
+impl Report {
+    pub fn is_safe(&self, tolerance: usize) -> bool {
+        let mut direction = None;
+        let mut failures = 0;
+        let mut skip_last = false;
+
+        for i in 1..self.0.len() {
+            match (
+                self.0[i]
+                    - self.0[i - if skip_last {
+                        skip_last = false;
+                        2
+                    } else {
+                        1
+                    }],
+                &direction,
+            ) {
+                /* Over limits */
+                (..=-4 | 4.., _) => {
+                    failures += 1;
+                    skip_last = true;
+                }
+
+                /* Decide on direction */
+                (..=-1, None) => direction = Some(Direction::Decreasing),
+                (1.., None) => direction = Some(Direction::Increasing),
+
+                /* Wrong Direction */
+                (1.., Some(Direction::Decreasing)) => {
+                    failures += 1;
+                    skip_last = true;
+                }
+                (..=-1, Some(Direction::Increasing)) => {
+                    failures += 1;
+                    skip_last = true;
+                }
+
+                /* No Change */
+                (0, _) => {
+                    failures += 1;
+                    skip_last = true;
+                }
+                _ => {}
+            }
+
+            if failures > tolerance {
+                return false;
+            }
+
+            if skip_last {
+                println!("SKIPPING {}", i);
+            }
+        }
+        true
+    }
+}
+
+impl From<&str> for Report {
+    fn from(value: &str) -> Self {
+        Self(
+            value
+                .split_whitespace()
+                .map(|v| v.parse::<i8>().expect("error while parsing input."))
+                .collect(),
+        )
+    }
+}
+
+type Data = Vec<Report>;
 impl DayImpl<Data> for Day<CURRENT_DAY> {
     fn init_test() -> (Self, Data) {
         Self::init(include_str!("test_inputs/test02.txt"))
     }
 
     fn expected_results() -> (Answer, Answer) {
-        (Answer::Number(0), Answer::Number(0))
+        (Answer::Number(2), Answer::Number(4))
     }
 
     fn init(input: &str) -> (Self, Data) {
-        (
-            Self {},
-            input
-                .lines()
-                .map(|v| v.parse::<u64>().expect("error while parsing input."))
-                .collect(),
-        )
+        (Self {}, input.lines().map(|l| l.into()).collect())
     }
 
     fn one(&self, data: &mut Data) -> Answer {
-        Answer::Number(data.len() as u64)
+        let mut safe_count = 0;
+        for report in data {
+            println!("{:?}", report);
+            if report.is_safe(0) {
+                safe_count += 1;
+            }
+        }
+
+        return Answer::Number(safe_count);
     }
 
     fn two(&self, data: &mut Data) -> Answer {
-        Answer::Number(data.len() as u64)
+        let mut safe_count = 0;
+        for report in data {
+            println!("{:?}", report);
+            if report.is_safe(1) {
+                println!("Safe!");
+                safe_count += 1;
+            }
+        }
+
+        return Answer::Number(safe_count);
     }
 }

src/days/test_inputs/test02.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