From 2d89799e442fecb805735b9f5cc3d7569221cb01 Mon Sep 17 00:00:00 2001
From: LeMoonStar <webmaster@unitcore.de>
Date: Wed, 4 Dec 2024 19:38:35 +0100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Day=204:=20Solved=20part=202!?=
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---
 README.md       |  4 ++--
 src/days/d04.rs | 49 ++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 5b0b40b..c42bf21 100644
--- a/README.md
+++ b/README.md
@@ -3,8 +3,8 @@
 [![About](https://img.shields.io/badge/Advent%20of%20Code-2024-brightgreen?style=flat-square)](https://adventofcode.com/2024/about)
 [![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-2.5-red?style=flat-square)
-![Stars](https://img.shields.io/badge/Stars-5-yellow?style=flat-square)
+![Days completed](https://img.shields.io/badge/Days%20completed-3.5-red?style=flat-square)
+![Stars](https://img.shields.io/badge/Stars-7-yellow?style=flat-square)
 
 > ⚠️ This README is copied from my previous years solution. It is not fully adopted to 2024 yet.
 
diff --git a/src/days/d04.rs b/src/days/d04.rs
index 564ed4b..d69ce05 100644
--- a/src/days/d04.rs
+++ b/src/days/d04.rs
@@ -116,6 +116,38 @@ impl LetterWall {
         directions
     }
 
+    #[rustfmt::skip]
+    fn is_cross_mas(&self, x: usize, y: usize) -> bool {
+        match(
+            self.at( x, y), self.at( x+1, y), self.at( x+2, y),
+            self.at( x, y+1), self.at( x+1, y+1), self.at( x+2, y+1),
+            self.at( x, y+2), self.at( x+1, y+2), self.at( x+2, y+2)
+        ) {
+            (
+                Some('M'), _,Some('S'),
+                _, Some('A'), _,
+                Some('M'), _, Some('S'),
+            ) => true,
+            (
+                Some('S'), _,Some('S'),
+                _, Some('A'), _,
+                Some('M'), _, Some('M'),
+            ) => true,
+            (
+                Some('M'), _,Some('M'),
+                _, Some('A'), _,
+                Some('S'), _, Some('S'),
+            ) => true,
+            (
+                Some('S'), _,Some('M'),
+                _, Some('A'), _,
+                Some('S'), _, Some('M'),
+            ) => true,
+            _ => false
+        }
+    }
+
+
     pub fn count_xmas(&self) -> u64 {
         let mut count = 0;
         for y in 0..self.0.len() {
@@ -125,6 +157,18 @@ impl LetterWall {
         }
         return count as u64;
     }
+
+    pub fn count_cross_mas(&self) -> u64 {
+        let mut count = 0;
+        for y in 0..self.0.len() {
+            for x in 0..self.0[0].len() {
+                if self.is_cross_mas(x, y) {
+                    count += 1;
+                }
+            }
+        }
+        return count as u64;
+    }
 }
 
 impl From<&str> for LetterWall {
@@ -141,7 +185,7 @@ impl DayImpl<Data> for Day<CURRENT_DAY> {
     }
 
     fn expected_results() -> (Answer, Answer) {
-        (Answer::Number(18), Answer::Number(0))
+        (Answer::Number(18), Answer::Number(9))
     }
 
     fn init(input: &str) -> (Self, Data) {
@@ -149,11 +193,10 @@ impl DayImpl<Data> for Day<CURRENT_DAY> {
     }
 
     fn one(&self, data: &mut Data) -> Answer {
-        // NOTE TO SELF: Actual result above 2334
         Answer::Number(data.count_xmas())
     }
 
     fn two(&self, data: &mut Data) -> Answer {
-        Answer::Number(0)
+        Answer::Number(data.count_cross_mas())
     }
 }