From 9098100658f857b36ee9df227fb3da5c813f315e Mon Sep 17 00:00:00 2001
From: Ben C <bwc9876@gmail.com>
Date: Thu, 5 Dec 2024 00:57:26 -0500
Subject: [PATCH] Day 5

---
 years/2024/src/day_5.rs             | 76 +++++++++++++++++++++++++++--
 years/2024/src/examples/day_5/1.txt | 28 +++++++++++
 years/2024/src/examples/day_5/2.txt | 28 +++++++++++
 3 files changed, 127 insertions(+), 5 deletions(-)

diff --git a/years/2024/src/day_5.rs b/years/2024/src/day_5.rs
index a87ca56..d8d4640 100644
--- a/years/2024/src/day_5.rs
+++ b/years/2024/src/day_5.rs
@@ -1,17 +1,83 @@
 
+use std::collections::{HashMap, HashSet};
+
 use advent_core::{Day, day_stuff, ex_for_day};
 
 pub struct Day5;
 
+#[derive(Clone, Debug)]
+pub struct Rules(HashMap<i64,Vec<i64>>);
+
+impl Rules {
+    pub fn take(&mut self, lhs: i64, rhs: i64) {
+        self.0.entry(lhs).and_modify(|seen| { seen.push(rhs); }).or_insert(vec![rhs]);
+    }
+
+    fn good(&self, up: &[i64]) -> bool {
+        let mut seen = HashSet::new();
+        for u in up.iter() {
+            if self.0.get(u).is_none_or(|should| should.iter().all(|s| !seen.contains(s))) {
+                seen.insert(*u);  
+            } else {
+                return false;
+            }
+        }
+        true
+    }
+
+    fn sort_to_rules(&self, up: &mut[i64]) {
+        while !self.good(up) {
+            self.sort_step(up);
+        }
+    }
+
+    fn sort_step(&self, up: &mut[i64]) {
+        for i in 0..up.len()-1 {
+            for j in i+1..up.len() {
+                if self.0.get(&up[j]).is_some_and(|shld| shld.contains(&up[i])) {
+                    up.swap(i, j);
+                } 
+            }
+        }
+    }
+}
+
 impl Day for Day5 {
 
-    day_stuff!(5, "", "");
+    day_stuff!(5, "143", "123", (Rules, Vec<Vec<i64>>));
 
-    fn part_1(_input: Self::Input) -> Option<String> {
-        None
+    fn part_1(input: Self::Input) -> Option<String> {
+        let (rules, updates) = input;
+        let ans = updates.into_iter().filter_map(|up| {
+            if rules.good(&up) {
+                Some(up[up.len() / 2])
+            } else {
+                None
+            }
+        }).sum::<i64>();
+        Some(ans.to_string())
     }
 
-    fn part_2(_input: Self::Input) -> Option<String> {
-        None
+    fn part_2(input: Self::Input) -> Option<String> {
+        let (rules, updates) = input;
+        let ans = updates.into_iter().filter_map(|mut up| {
+            if !rules.good(&up) {
+                rules.sort_to_rules(&mut up);
+                Some(up[up.len() / 2])
+            } else {
+                None
+            }
+        }).sum::<i64>();
+        Some(ans.to_string())
+    }
+    
+    fn parse_input(input: &str) -> Self::Input {
+        let (rules, updates) = input.split_once("\n\n").unwrap();
+        let mut rules_o = Rules(HashMap::with_capacity(50));
+        for l in rules.lines() {
+            let (lhs, rhs) = l.split_once('|').unwrap();
+            rules_o.take(lhs.parse().unwrap(), rhs.parse().unwrap());
+        }
+        (rules_o, updates.split('\n').map(|l| l.split(',').map(|x| x.parse().unwrap()).collect()).collect())
     }
 }
diff --git a/years/2024/src/examples/day_5/1.txt b/years/2024/src/examples/day_5/1.txt
index e69de29..d4d4441 100644
--- a/years/2024/src/examples/day_5/1.txt
+++ b/years/2024/src/examples/day_5/1.txt
@@ -0,0 +1,28 @@
+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47
\ No newline at end of file
diff --git a/years/2024/src/examples/day_5/2.txt b/years/2024/src/examples/day_5/2.txt
index e69de29..d4d4441 100644
--- a/years/2024/src/examples/day_5/2.txt
+++ b/years/2024/src/examples/day_5/2.txt
@@ -0,0 +1,28 @@
+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47
\ No newline at end of file
-- 
2.51.2