Day 10 (simplified)

day10/part1.py

@@ -1,14 +1,12 @@
-import numpy as np
+from collections import defaultdict
 
 lines = sorted(int(x.strip()) for x in open("input.txt"))
 
-lines.append(lines[-1]+3)
-lines.insert(0, 0)
-lines = np.array(lines)
+cnt = defaultdict(int)
+last = 0
+for line in lines:
+    mov = line - last
+    last = line
+    cnt[mov] += 1
 
-diff = lines[1:] - lines[:-1]
-unique, counts = np.unique(diff, return_counts=True)
-cnt = dict(zip(unique, counts))
-
-print(cnt)
-print(cnt[1]*cnt[3])
+print(cnt[1] * (cnt[3]+1))

day10/part2.py

@@ -1,27 +1,12 @@
 lines = sorted(int(x.strip()) for x in open("input.txt"))
 
-one_count = 0
-possibilities = 1
-one_cache = [1]
-
-
-def count_one_possibilities(one_cnt: int):
-    for idx in range(len(one_cache), one_cnt+1):
-        one_cache.append(sum(one_cache[-3:]))
-    return one_cache[one_cnt]
-
-
-# only 3 and 1 differences are available
-# 3 has to be taken / calculate possibilities for 1 hops
-prev = 0
+prevs = [0, 0, 0, 1]
+last = 0
 for line in lines:
-    diff = line-prev
-    prev = line
-    if diff == 1:
-        one_count += 1
-    elif diff == 3:
-        possibilities *= count_one_possibilities(one_count)
-        one_count = 0
-possibilities *= count_one_possibilities(one_count)
+    mov = line - last
+    last = line
+    if mov > 0:
+        prevs = prevs[mov:] + [0]*mov
+        prevs[-1] = sum(prevs)
 
-print(possibilities)  # 64793042714624
+print(prevs[-1])