day 10

10/10.py

@@ -0,0 +1,47 @@
+#!/usr/bin/python3
+
+import sys
+from functools import lru_cache 
+
+jolts = 0
+adapt = [0]
+
+for line in sys.stdin:
+    i = int(line.rstrip())
+    adapt.append(i)
+adapt = sorted(adapt)
+
+countjolts = {}
+countjolts[3] = 1
+valid = {}
+
+for a in adapt:
+    diff = a - jolts
+    jolts = a
+    if diff not in countjolts:
+        countjolts[diff] = 1
+    else:
+        countjolts[diff] = countjolts[diff] + 1
+print(1, countjolts[3] * countjolts[1])
+
+# this is witchcraft
+@lru_cache
+def find_perms(adapt, n):
+    current = adapt[n]
+    pv = 0
+    l = n + 4
+    if l > len(adapt):
+        l = len(adapt)
+
+    for i in range(n+1, l):
+        if adapt[i] > current + 3:
+            continue
+
+        pv = pv + find_perms(adapt, i)
+
+    if pv == 0:
+        return 1
+
+    return pv
+
+print(2, find_perms(tuple(adapt),0))