Cleanup code and store invalid pages for part 2

day_05/src/main.rs

@@ -15,13 +15,14 @@ fn main() -> Result<(), Box<dyn Error>> {
             &args[0]
         )
     }
-    let input_file_string = &args[1];
+    let input_file = &args[1];
 
-    let buffer = BufReader::new(File::open(input_file_string)?);
+    let buffer = BufReader::new(File::open(input_file)?);
 
     let mut rules_stage = true;
     let mut page_rules: HashMap<i64, HashSet<i64>> = HashMap::new();
     let mut valid_page_updates: Vec<Vec<i64>> = Vec::new();
+    let mut invalid_page_updates: Vec<Vec<i64>> = Vec::new();
     for line in buffer.lines() {
         let line = line?;
         if rules_stage {
@@ -30,7 +31,7 @@ fn main() -> Result<(), Box<dyn Error>> {
             if line.is_empty() {
                 // Blank line means end of rules
                 rules_stage = false;
-                println!("Page Rules: {:?}", page_rules);
+                // println!("Page Rules: {:?}", page_rules);
                 continue;
             }
             let split_line: Vec<&str> = line.split("|").collect();
@@ -42,8 +43,8 @@ fn main() -> Result<(), Box<dyn Error>> {
             let key = split_line[0].parse::<i64>()?;
             let value = split_line[1].parse::<i64>()?;
             match page_rules.get_mut(&key) {
-                Some(rule) => {
-                    rule.insert(value);
+                Some(rule_set) => {
+                    rule_set.insert(value);
                 }
                 None => {
                     let mut new_rule_set = HashSet::new();
@@ -53,14 +54,14 @@ fn main() -> Result<(), Box<dyn Error>> {
             }
         } else {
             // Stage 2: check updates
-            let update_page_nums: Vec<i64> = line
+            let page_update: Vec<i64> = line
                 .split(",")
                 .map(|v| v.parse::<_>())
                 .collect::<Result<_, _>>()?;
 
             let mut prev_pages: HashSet<i64> = HashSet::new();
             let mut is_valid = true;
-            for page_num in update_page_nums.iter() {
+            for page_num in page_update.iter() {
                 if let Some(rule_set) = page_rules.get(page_num) {
                     if !prev_pages.is_disjoint(rule_set) {
                         is_valid = false;
@@ -70,7 +71,9 @@ fn main() -> Result<(), Box<dyn Error>> {
                 }
             }
             if is_valid {
-                valid_page_updates.push(update_page_nums);
+                valid_page_updates.push(page_update);
+            } else {
+                invalid_page_updates.push(page_update);
             }
         }
     }