Day 5 problems complete

crates/day_5/src/day_5.rs

@@ -19,6 +19,7 @@ pub struct Day5
 	pub final_result: i32,
 
 	rules: Vec<Rule>,
+	updates: Vec<Update>,
 }
 
 //|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
@@ -28,19 +29,75 @@ impl Day5
 {
 	pub fn new() -> Day5
 	{
-		Day5 { data_set: DataSet::Test, run_mode: RunMode::FirstCase, do_debug_prints: false, final_result: 0, rules: vec![] }
+		Day5 { data_set: DataSet::Test, run_mode: RunMode::FirstCase, 
+			do_debug_prints: false, final_result: 0, rules: vec![], updates: vec![] }
 	}
 
 	fn solve_first_case(self: &mut Self) -> String
 	{
+		// verify all updates
+		let valid_count = check_updates(&mut self.updates, &self.rules, self.do_debug_prints);
 
+		if self.do_debug_prints
+		{
+			println!("DEBUG: valid updates found: {}", valid_count);
+		}
+
+		// Sum the middle page of each valid update
+		let mut sum = 0;
+		for update in &self.updates
+		{
+			if UpdateStatus::Valid == update.status
+			{
+				let mid_idx = update.pages.len() / 2;
+				sum += update.pages[mid_idx];
+			}
+		}
+		
+		self.final_result = sum;
 		self.final_result.to_string()
 	}
 
 	fn solve_second_case(self: &mut Self) -> String
 	{
+		// verify
+		let _ = check_updates(&mut self.updates, &self.rules, self.do_debug_prints);
+
+		// fix any broken updates and sum their mid pages
+		let mut sum = 0;
+		for update in &mut self.updates
+		{
+			if UpdateStatus::Valid == update.status
+			{
+				continue;
+			}
+
+			let mut fixed = false;
+			let mut i = 0;
+			while i < self.rules.len()
+			{
+				if !self.rules[i].verify_update(&update.pages, self.do_debug_prints)
+				{
+					self.rules[i].make_valid(&mut update.pages, self.do_debug_prints);
+					i = 0;
+					fixed = true;
+				}
+				else
+				{
+					i += 1;
+				}
+			}
 
+			if fixed && self.do_debug_prints
+			{
+				println!("DEBUG: Fixed update: {:#?}", update.pages);
+			}
+
+			let mid_idx = update.pages.len() / 2;
+			sum += update.pages[mid_idx];
+		}
 
+		self.final_result = sum;
 		self.final_result.to_string()
 	}
 }
@@ -52,7 +109,7 @@ impl Solver for Day5
 {
 	fn print_test() 
 	{
-		println!("DAY 4 TEST PRINT");
+		println!("DAY 5 TEST PRINT");
 	}
 
 	fn init(self: &mut Self, data_set: DataSet, run_mode: RunMode, enable_debug_prints: bool) 
@@ -81,9 +138,35 @@ impl Solver for Day5
 		let data_split = data.split(split_pattern);
 		for row in data_split
 		{
+			if self.do_debug_prints
+			{
+				println!("DEBUG: Loading row: {}", row);
+			}
+
+			if row.is_empty()
+			{
+				if self.do_debug_prints
+				{
+					println!("DEBUG: Skipping empty row");
+				}
+				continue;
+			}
+
+			// Rules contain "|", update lists do not
 			if row.contains("|")
 			{
-				self.rules.push(Rule::parse(row).expect(&format!("Failed to create rule from: {}", row) ));
+				self.rules.push(Rule::parse(row).expect(&format!("ERROR: Failed to create rule from: {}", row) ));
+			}
+			else
+			{
+				let mut pages: Vec<i32> = vec![];
+				for page in row.split(",")
+				{
+					let page_i = page.parse::<i32>().expect(&format!("ERROR: Failed to parse update page: {}", page));
+					pages.push(page_i);
+				}
+
+				self.updates.push(Update::new(pages));
 			}
 		}
 
@@ -92,9 +175,22 @@ impl Solver for Day5
 			println!("Rules:");
 			for rule in &self.rules
 			{
-				println!("\tRule: {}|{}", rule.first, rule.second);
+				println!("\t{}|{}", rule.first, rule.second);
 			}
+
+			println!("Updates:");
+			for update in &self.updates
+			{
+				print!("\t");
+				for page in &update.pages
+				{
+					print!("{},", page);
 				}
+				println!();
+			}
+		}
+
+
 
 	}
 
@@ -120,6 +216,30 @@ impl Solver for Day5
 //				EXTRA STUFF
 //|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 
+fn check_updates(updates: &mut Vec<Update>, rules: &Vec<Rule>, enable_debug_prints: bool) -> i32
+{
+	let mut valid_count = 0;
+	for update in updates
+	{
+		for rules in rules
+		{
+			if !rules.verify_update(&update.pages, enable_debug_prints)
+			{
+				update.status = UpdateStatus::Invalid;
+				break;
+			}
+		}
+
+		if UpdateStatus::Unknown == update.status
+		{
+			update.status = UpdateStatus::Valid;
+			valid_count += 1;
+		}
+	}
+
+	return valid_count;
+}
+
 #[derive(Copy, Clone, Debug)]
 struct Rule
 {
@@ -129,7 +249,7 @@ struct Rule
 
 impl Rule
 {
-	fn new(first: i32, second: i32) -> Rule
+	fn _new(first: i32, second: i32) -> Rule
 	{
 		Rule { first, second }
 	}
@@ -150,4 +270,79 @@ impl Rule
 
 		Ok(Rule { first, second})
 	}
+
+	fn verify_update(self: &Rule, update: &Vec<i32>, enable_debug_output: bool) -> bool
+	{
+		let mut found_second = false;
+
+		for page in update
+		{
+			if *page == self.first
+			{
+				if found_second
+				{
+					if enable_debug_output
+					{
+						println!("DEBUG: Update ({:#?}) fails rule: {}|{} -- found first after second", update, self.first, self.second);
+					}
+					return false;
+				}
+			}
+
+			if *page == self.second
+			{
+				found_second = true;
+			}
+		}
+
+		return true;
+	}
+
+	fn make_valid(self: &Rule, update: &mut Vec<i32>, enable_debug_output: bool)
+	{
+		let mut first_idx  = 0;
+		let mut second_idx = 0;
+
+		for (i, page) in update.iter().enumerate()
+		{
+			if *page == self.first
+			{
+				first_idx = i;
+			}
+
+			if *page == self.second
+			{
+				second_idx = i;
+			}
+		}
+
+		if first_idx > second_idx
+		{
+			update.swap(first_idx, second_idx);
+		}
+	}
+}
+
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+enum UpdateStatus
+{
+	Valid,
+	Invalid,
+	Unknown,
+}
+
+#[derive(Clone, Debug)]
+struct Update
+{
+	pages: Vec<i32>,
+	status: UpdateStatus,
+}
+
+impl Update
+{
+	fn new(pages: Vec<i32>) -> Update
+	{
+		Update { pages, status: UpdateStatus::Unknown }
+	}
 }

src/main.rs

@@ -71,14 +71,14 @@ fn main()
 
     // DAY 5
     let mut day_5 = Day5::new();
-    day_5.init(DataSet::Test, RunMode::FirstCase, true);
+    day_5.init(DataSet::Full, RunMode::FirstCase, false);
     let day5_result = day_5.solve();
     println!("Day 5 Part 1 Final Result: {}", day5_result);
 
-    // let mut day_5 = Day5::new();
-    // day_5.init(DataSet::Test, RunMode::SecondCase, false);
-    // let day5_result = day_5.solve();
-    // println!("Day 5 Part 2 Final Result: {}", day5_result);   
+    let mut day_5 = Day5::new();
+    day_5.init(DataSet::Full, RunMode::SecondCase, false);
+    let day5_result = day_5.solve();
+    println!("Day 5 Part 2 Final Result: {}", day5_result);   
     
     println!("-------------------------");