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))