Try day 14

[max/advent_of_code_2021.git] / 14_2.py

diff --git a/14_2.py b/14_2.py
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+""" Pair insertion """
+import pprint
+import collections
+
+insertion_rules = {}
+
+polymer_pairs = collections.defaultdict(int)
+
+letter_count = collections.defaultdict(int)
+
+with open("14_input.txt") as f:
+    polymer_template = f.readline().strip()
+    f.readline()
+
+    for line in f:
+        pair, insert = line.strip().split(" -> ")
+        insertion_rules[pair] = insert
+
+for i in range(len(polymer_template) - 1):
+    pair = str(polymer_template[i:i+2])
+    polymer_pairs[str(polymer_template[i:i+2])] += 1
+
+print(polymer_pairs)
+
+for _ in range(40):
+    new_polymer_pairs = collections.defaultdict(int)
+    for pair, n in polymer_pairs.items():
+        insert = insertion_rules[pair]
+
+        new_polymer_pairs[f"{pair[0]}{insert}"] += n
+        new_polymer_pairs[f"{insert}{pair[0]}"] += n
+        letter_count[insert] += n
+
+    polymer_pairs = new_polymer_pairs
+
+print(letter_count)
+print(max(letter_count.values()) - min(letter_count.values()))