d22

1 files changed, 65 insertions, 0 deletions

diff --git a/20/py/d22.py b/20/py/d22.py
new file mode 100644
index 0000000..e32d01a
--- /dev/null
+++ b/20/py/d22.py
@@ -0,0 +1,65 @@
+import aoc20
+import sys
+from collections import deque
+import functools
+import itertools
+
+
+def pt1(_in):
+    _in = "".join(_in)
+    player1 = deque([int(n) for n in _in.split("\n\n")[0].split("\n")[1:]])
+    player2 = deque([int(n) for n in _in.split("\n\n")[1].split("\n")[1:-1]])
+
+    while all((player1, player2)):
+        c1, c2 = player1.popleft(), player2.popleft()
+        if c1 > c2:
+            player1.append(c1)
+            player1.append(c2)
+        else:
+            player2.append(c2)
+            player2.append(c1)
+
+    return sum((i+1) * v
+               for i, v in enumerate(reversed(player1 if player1 else player2)))
+
+
+mem = dict()
+def play(player1, player2):
+    call_state = tuple((tuple(player1), tuple(player2)))
+    if call_state in mem:
+        return mem[call_state]
+    seen = set()
+    while all((player1, player2)):
+        state = tuple((tuple(player1), tuple(player2)))
+        if state in seen:
+            mem[call_state] = 1
+            return 1
+        seen.add(state)
+        c1, c2 = player1.popleft(), player2.popleft()
+        if all(len(p) >= c for c, p in zip((c1,c2), (player1, player2))):
+            win = play(deque(itertools.islice(player1, 0, c1)), deque(itertools.islice(player2, 0, c2)))
+        else:
+            win = 1 if c1 > c2 else 2
+        if win == 1:
+            player1.append(c1)
+            player1.append(c2)
+        else:
+            player2.append(c2)
+            player2.append(c1)
+    mem[call_state] = 1 if player1 else 2
+    return 1 if player1 else 2
+
+
+
+def pt2(_in):
+    _in = "".join(_in)
+    player1 = deque([int(n) for n in _in.split("\n\n")[0].split("\n")[1:]])
+    player2 = deque([int(n) for n in _in.split("\n\n")[1].split("\n")[1:-1]])
+    play(player1, player2)
+    return sum((i+1) * v
+               for i, v in enumerate(reversed(player1 if player1 else player2)))
+
+if __name__ == "__main__":
+    _in = aoc20.read_input(sys.argv[1:], 22)
+    print(pt1(_in))
+    print(pt2(_in))