submit day 7 part 2

src/bin/07.rs

@@ -1,47 +1,58 @@
 advent_of_code::solution!(7);
 
 pub fn part_one(input: &str) -> Option<u32> {
+    Some(get_bids_sum(input, false))
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    Some(get_bids_sum(input, true))
+}
+
+fn get_bids_sum(input: &str, has_jokers: bool) -> u32 {
     let mut hands = input
         .lines()
         .map(|line| {
             let (left, right) = line.split_at(6);
-            (get_hand_rank(&left[..5]), right.parse::<u32>().unwrap())
+            (
+                get_hand_rank(&left[..5], has_jokers),
+                right.parse::<u32>().unwrap(),
+            )
         })
         .collect::<Vec<_>>();
 
     hands.sort_by_key(|(rank, _)| *rank);
 
-    let sum = hands
+    hands
         .iter()
         .enumerate()
         .fold(0, |sum, (index, (_, current_bid))| {
             sum + (index as u32 + 1) * current_bid
-        });
-
-    Some(sum)
-}
-
-pub fn part_two(input: &str) -> Option<u32> {
-    None
+        })
 }
 
-fn get_hand_rank(hand: &str) -> u32 {
-    let kind_distribution = get_kind_distribution(hand);
+fn get_hand_rank(hand: &str, has_jokers: bool) -> u32 {
+    let kind_distribution = get_kind_distribution(hand, has_jokers);
 
     let mut hand_rank = get_hand_type_rank(kind_distribution);
 
     for card in hand.chars() {
         hand_rank <<= 4;
-        hand_rank |= get_rank_for_card(&card);
+        hand_rank |= get_rank_for_card(&card, has_jokers);
     }
 
     hand_rank
 }
 
-fn get_kind_distribution(hand: &str) -> [u32; 5] {
+fn get_kind_distribution(hand: &str, has_jokers: bool) -> [u32; 5] {
     let mut kind_values: [Option<(char, u32)>; 5] = [None; 5];
+    let mut jokers_count = 0;
 
     for card in hand.chars() {
+        if card == 'J' && has_jokers {
+            jokers_count += 1;
+            continue;
+        }
+
         for option in kind_values.iter_mut() {
             if let Some((current_card, count)) = option {
                 if *current_card == card {
@@ -59,6 +70,10 @@ fn get_kind_distribution(hand: &str) -> [u32; 5] {
 
     kind_distribution.sort_by(|a, b| b.cmp(a));
 
+    if jokers_count > 0 {
+        kind_distribution[0] += jokers_count;
+    }
+
     kind_distribution
 }
 
@@ -75,21 +90,27 @@ fn get_hand_type_rank(kind_distribution: [u32; 5]) -> u32 {
     }
 }
 
-fn get_rank_for_card(card: &char) -> u32 {
+fn get_rank_for_card(card: &char, has_jokers: bool) -> u32 {
     match card {
-        'A' => 0xc,
-        'K' => 0xb,
-        'Q' => 0xa,
-        'J' => 0x9,
-        'T' => 0x8,
-        '9' => 0x7,
-        '8' => 0x6,
-        '7' => 0x5,
-        '6' => 0x4,
-        '5' => 0x3,
-        '4' => 0x2,
-        '3' => 0x1,
-        '2' => 0x0,
+        'A' => 0xd,
+        'K' => 0xc,
+        'Q' => 0xb,
+        'J' => {
+            if has_jokers {
+                0x0
+            } else {
+                0xa
+            }
+        }
+        'T' => 0x9,
+        '9' => 0x8,
+        '8' => 0x7,
+        '7' => 0x6,
+        '6' => 0x5,
+        '5' => 0x4,
+        '4' => 0x3,
+        '3' => 0x2,
+        '2' => 0x1,
         _ => panic!("Invalid card"),
     }
 }
@@ -107,6 +128,6 @@ mod tests {
     #[test]
     fn test_part_two() {
         let result = part_two(&advent_of_code::template::read_file("examples", DAY));
-        assert_eq!(result, None);
+        assert_eq!(result, Some(5905));
     }
 }