Solve 2018 day 22 and 2019 day 20

2018/d22.py

@@ -0,0 +1,89 @@
+from lib import get_data, str_to_ints, A_Star
+
+data = get_data(__file__)
+
+depth, x_target, y_target = str_to_ints(data)
+# depth, x_target, y_target = 510, 10, 10
+# depth, x_target, y_target = 9171, 7, 721
+# print(depth, x_target, y_target)
+
+x_area_max = x_target * 10
+y_area_max = y_target * 10
+
+maze = [[None for _ in range(x_area_max + 1)] for _ in range(y_area_max + 1)]
+
+maze[0][0] = 0
+maze[y_target][x_target] = 0
+
+mod = 20183
+for x in range(x_area_max + 1):
+    maze[0][x] = x * 16807 % mod
+
+for y in range(y_area_max + 1):
+    maze[y][0] = y * 48271 % mod
+
+for y in range(1, y_area_max + 1):
+    for x in range(1, x_area_max + 1):
+        if x == x_target and y == y_target:
+            continue
+        assert maze[y][x] is None
+        geo_index = ((maze[y][x - 1] + depth) * (maze[y - 1][x] + depth)) % mod
+        maze[y][x] = geo_index
+
+t = 0
+for y in range(y_target + 1):
+    for x in range(x_target + 1):
+        t += ((maze[y][x] + depth) % mod) % 3
+print(t)
+
+for y in range(y_area_max + 1):
+    for x in range(x_area_max + 1):
+        maze[y][x] = ((maze[y][x] + depth) % mod) % 3
+
+
+def allowed(area, tool):
+    # 0 = rocky, 1 = wet, 2 = narrow
+    # 0 = torch, 1 = climbing, 2 = neither
+    return (
+        (area == 0 and (tool in [0, 1]))
+        or (area == 1 and (tool in [1, 2]))
+        or (area == 2 and (tool in [0, 2]))
+    )
+
+
+def neighbors(state):
+    x, y, tool = state
+    r = []
+    area = maze[y][x]
+    for t in range(3):
+        if allowed(area, t) and t != tool:
+            r.append((x, y, t))
+
+    for dx, dy in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
+        nx, ny = x + dx, y + dy
+        if not (nx >= 0 and nx < x_area_max and ny >= 0 and ny < y_area_max):
+            continue
+        if not allowed(maze[ny][nx], tool):
+            continue
+        r.append((nx, ny, tool))
+    return r
+
+
+def distance(a, b):
+    if a == 0:
+        return 0
+    elif a[2] != b[2]:
+        assert a[0] == b[0] and a[1] == b[1]
+        return 7
+    else:
+        return 1
+
+
+a = A_Star(
+    starts=[(0, 0, 0)],
+    is_goal=lambda s: s[0] == x_target and s[1] == y_target and s[2] == 0,
+    h=lambda s: abs(s[0] - x_target) + abs(s[1] - y_target),
+    d=distance,
+    neighbors=neighbors,
+)
+print(a.cost)