Day 07 Part 2 complete (Ignore the messy code!)

src/solutions/day07.rs

@@ -20,7 +20,7 @@ impl Solution for Day07 {
         &self,
         input: &mut Vec<String>,
     ) -> Result<Box<dyn std::fmt::Display + Sync>, Box<dyn std::error::Error>> {
-        let hands = self.get_hands_from_string(input)?;
+        let hands = self.get_hands_from_string(input, false)?;
         let mut totals = vec![];
 
         for hand in hands.iter() {
@@ -37,7 +37,6 @@ impl Solution for Day07 {
 
         let mut score: u64 = 0;
         for (i, cards) in totals.iter().enumerate() {
-            println!("{} * {}, {:?} {}", i + 1, cards.1, cards.0, cards.2);
             score += (cards.1 * (i + 1) as u32) as u64;
         }
         Ok(Box::new(score))
@@ -45,9 +44,34 @@ impl Solution for Day07 {
 
     fn part2(
         &self,
-        _input: &mut Vec<String>,
+        input: &mut Vec<String>,
     ) -> Result<Box<dyn std::fmt::Display + Sync>, Box<dyn std::error::Error>> {
-        Ok(Box::new("Ready"))
+        let hands = self.get_hands_from_string(input, true)?;
+        let mut totals = vec![];
+
+        for hand in hands.iter() {
+            let adapted_hand = self.replace_wildcard(&hand.0)?;
+            totals.push((
+                hand.0.clone(),
+                hand.1,
+                self.get_hand_type(&adapted_hand)? as u32,
+            ));
+            println!("{:?}", hand);
+        }
+
+        totals.sort_by(|a, b| {
+            if a.2 == b.2 {
+                a.0.partial_cmp(&b.0).unwrap()
+            } else {
+                (a.2 as u32).cmp(&(b.2 as u32))
+            }
+        });
+
+        let mut score: u64 = 0;
+        for (i, cards) in totals.iter().enumerate() {
+            score += (cards.1 * (i + 1) as u32) as u64;
+        }
+        Ok(Box::new(score))
     }
 
     fn get_day(&self) -> u8 {
@@ -59,6 +83,7 @@ impl Day07 {
     fn get_hands_from_string(
         &self,
         input: &mut Vec<String>,
+        wildcard: bool,
     ) -> Result<Vec<(Vec<u32>, u32)>, Box<dyn std::error::Error>> {
         let mut hands = vec![];
 
@@ -71,7 +96,13 @@ impl Day07 {
             for i in card.chars() {
                 hand.push(match i {
                     'T' => 10,
-                    'J' => 11,
+                    'J' => {
+                        if wildcard {
+                            0
+                        } else {
+                            11
+                        }
+                    }
                     'Q' => 12,
                     'K' => 13,
                     'A' => 14,
@@ -128,6 +159,51 @@ impl Day07 {
         // High Card
         Ok(Hands::HC)
     }
+
+    fn replace_wildcard<'a>(
+        &self,
+        input: &Vec<u32>,
+    ) -> Result<Vec<u32>, Box<dyn std::error::Error>> {
+        let mut map_cards = HashMap::new();
+
+        for c in input.iter() {
+            map_cards.entry(c).and_modify(|c| *c += 1).or_insert(1u32);
+        }
+
+        // Get the wildcard count from the map and replace with the most common card
+        let wc_count = *map_cards.get(&0).unwrap_or(&0);
+
+        // Remove wildcards as we have already
+        map_cards.remove_entry(&0);
+
+        // Find the maximum frequency
+        let max_frequency = map_cards.values().cloned().max().unwrap_or(0);
+
+        // Filter numbers with the maximum frequency
+        let most_frequenct_cards: Vec<u32> = map_cards
+            .clone()
+            .into_iter()
+            .filter(|&(_, frequency)| frequency == max_frequency)
+            .map(|(number, _)| *number)
+            .collect::<Vec<u32>>();
+
+        if most_frequenct_cards.len() == 0 {
+            return Ok(input.clone());
+        }
+
+        map_cards.entry(&most_frequenct_cards[0]).and_modify(|v| {
+            *v += wc_count;
+        });
+
+        let result: Vec<u32> = map_cards
+            .into_iter()
+            .flat_map(|(key, count)| vec![*key; count as usize])
+            .collect();
+
+        println!("Replaced: {:?}", result);
+
+        Ok(result)
+    }
 }
 
 /// Test from puzzle input
@@ -167,6 +243,6 @@ mod test {
             .unwrap()
             .to_string();
 
-        assert_eq!(answer, "Ready");
+        assert_eq!(answer, "5905");
     }
 }