tree

y2021/p05.py

+from collections import Counter
+from itertools import cycle
+from math import copysign
+
+
+sign = lambda n: int(copysign(1, n))
+points = {'flat': Counter(), 'diag': Counter()}
+for line in text.splitlines():
+    x1, y1, x2, y2 = [int(n) for n in re.findall(r'\d+', line)]
+    xs = [*range(x1, x2, sign(x2 - x1)), x2]
+    ys = [*range(y1, y2, sign(y2 - y1)), y2]
+    if len(xs) == 1:
+        points['flat'].update(zip(cycle(xs), ys))
+    elif len(ys) == 1:
+        points['flat'].update(zip(xs, cycle(ys)))
+    else:
+        points['diag'].update(zip(xs, ys))
+ans1 = sum(v > 1 for v in (points['flat']).values())
+ans2 = sum(v > 1 for v in (points['flat'] + points['diag']).values())