Solve 2019 day 14 and 15

2019/d15.py

@@ -0,0 +1,116 @@
+from lib import get_data, str_to_ints, add2
+from collections import deque
+from d9 import Amp
+
+
+DIRS = {1: (-1, 0), 2: (1, 0), 3: (0, -1), 4: (0, 1)}
+PATH_REVERSED = {1: 2, 2: 1, 3: 4, 4: 3}
+
+
+def print_field(fields, walls, pos):
+    dim = 40
+    for y in range(-dim, dim + 1):
+        row = ""
+        for x in range(-dim, dim + 1):
+            if (y, x) == pos:
+                row += "X"
+            elif (y, x) in fields:
+                row += "."
+            elif (y, x) in walls:
+                row += "|"
+            else:
+                row += " "
+        print(row)
+
+
+def part_1(data):
+    xs = str_to_ints(data)
+    a = Amp(xs)
+
+    walls = set()
+    pos = (0, 0)
+    target = None
+    dir = None
+    path = []
+    dir_cmds_for_pos = {pos: [1, 2, 3, 4]}
+
+    while not a.done:
+        if len(dir_cmds_for_pos[pos]) > 0:
+            dir_cmd = dir_cmds_for_pos[pos].pop()
+            dir = DIRS[dir_cmd]
+
+            new_pos = add2(pos, dir)
+            if new_pos in dir_cmds_for_pos:
+                continue
+
+            a.feed(dir_cmd)
+            a.go()
+            status = a.pop()
+
+            if status == 0:
+                walls.add(new_pos)
+            elif status == 1:
+                pos = new_pos
+                path.append(dir_cmd)
+            elif status == 2:
+                pos = new_pos
+                path.append(dir_cmd)
+                target = pos
+
+            if pos not in dir_cmds_for_pos:
+                dir_cmds_for_pos[pos] = [1, 2, 3, 4]
+
+        elif len(path) > 0:
+            dir_cmd = PATH_REVERSED[path.pop()]
+            dir = DIRS[dir_cmd]
+            pos = add2(pos, dir)
+            a.feed(dir_cmd)
+            a.go()
+            status = a.pop()
+            assert status == 1 or status == 2
+        elif target is not None:
+            break
+        else:
+            break
+    fields = set(dir_cmds_for_pos.keys())
+    # print_field(fields, walls, pos)
+
+    seen = set()
+    to_visit = [(0, 0)]
+    steps = 0
+    while len(to_visit) > 0:
+        new = []
+        for current in to_visit:
+            if current == target:
+                print(steps)
+            seen.add(current)
+            for dir in DIRS.values():
+                nb = add2(current, dir)
+                if nb in fields and nb not in seen:
+                    new.append(nb)
+        to_visit = new
+        steps += 1
+
+    seen = set()
+    to_visit = [target]
+    steps = 0
+    while len(to_visit) > 0:
+        new = []
+        for current in to_visit:
+            seen.add(current)
+            for dir in DIRS.values():
+                nb = add2(current, dir)
+                if nb in fields and nb not in seen:
+                    new.append(nb)
+        to_visit = new
+        steps += 1
+    print(steps - 1)
+
+
+def main():
+    data = get_data(__file__)
+    part_1(data)
+
+
+if __name__ == "__main__":
+    main()