catch up on solutions up to day 20

1 files changed, 30 insertions, 0 deletions

diff --git a/day14.py b/day14.py
new file mode 100644
index 0000000..f04d327
--- /dev/null
+++ b/day14.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+from collections import defaultdict
+
+with open('day14.txt') as data:
+    template = next(data).strip()
+    next(data)
+    rules = {}
+    for line in data:
+        k, v = line.strip().split(' -> ')
+        rules[k] = v
+
+def polymerize(steps=10):
+    pairs = defaultdict(int)
+    for i in range(len(template) - 1):
+        pairs[template[i] + template[i+1]] += 1
+
+    for i in range(steps):
+        update = defaultdict(int)
+        for k, v in pairs.items():
+            update[k[0] + rules[k]] += v
+            update[rules[k] + k[1]] += v
+        pairs = update
+
+    counts = defaultdict(int)
+    for k, v in pairs.items():
+        counts[k[0]] += v
+    return max(counts.values()) - min(counts.values()) - 1
+
+print(polymerize())
+print(polymerize(40))