day 18 part 2 python

day18.py

@@ -0,0 +1,67 @@
+def parse_input(input: list[str]):
+    return [tuple(map(lambda f: int(f), cl.split(','))) for cl in input]
+
+
+with open('input/day18.txt', 'r') as f:
+    data = f.read()
+
+
+points = parse_input(data.strip().split('\n'))
+
+# points = set([
+#     (5, 4),
+#     (4, 2),
+#     (4, 5),
+#     (3, 0),
+#     (2, 1),
+#     (6, 3),
+#     (2, 4),
+#     (1, 5),
+#     (0, 6),
+#     (3, 3),
+#     (2, 6),
+#     (5, 1),
+#     (1, 2),
+#     (5, 5),
+#     (2, 5),
+#     (6, 5),
+#     (1, 4),
+#     (0, 4),
+#     (6, 4),
+#     (1, 1),
+#     (6, 1),
+#     (1, 0),
+#     (0, 5),
+#     (1, 6),
+#     (2, 0),
+# ][:12])
+# goal = (6, 6)
+# w = 6
+
+
+def sp(points, w):
+    visited = dict()
+    stack = [(0, 0, 0)]
+    while len(stack) > 0:
+        (x, y, c) = stack.pop(0)
+        if (x, y) == (w, w):
+            return c
+
+        if (x, y) in visited:
+            continue
+        visited[(x, y)] = c
+
+        for (a, b) in [(x+nx, y+ny) for (nx, ny) in [(0, 1), (1, 0), (0, -1), (-1, 0)]]:
+            if 0 <= a <= w and 0 <= b <= w and (a, b) not in points:
+                stack.append((a, b, c + 1))
+
+    return None
+
+
+print("task 1: " + str(sp(set(points[:1024]), 70)))
+
+for take in range(1024, len(points)):
+    solution = sp(set(points[:take]), 70)
+    if not solution:
+        print("task 2: " + str(points[take - 1]))
+        break