day 23, fast with codon: <1s

d23/run.co.py

@@ -0,0 +1,53 @@
+import sys
+from typing import Tuple
+
+E = { (y,x) for y,l in enumerate(sys.stdin.read().splitlines())
+	for x,c in enumerate(l)
+		if c == '#' }
+
+def dim():
+	minx = min(x for (_,x) in E)
+	maxx = max(x for (_,x) in E)
+	miny = min(y for (y,_) in E)
+	maxy = max(y for (y,_) in E)
+	return (maxx-minx+1,maxy-miny+1) # W,H
+
+MARK = (-9999,-9999)
+for r in range(int(sys.argv[1])):  # rounds
+	P = dict()  # { new_pos: old_pos }
+	for (y,x) in E:  # for each elve
+		can1 = (y-1,x-1) not in E
+		can2 = (y-1,x) not in E
+		can3 = (y-1,x+1) not in E
+		can4 = (y,x+1) not in E
+		can5 = (y+1,x+1) not in E
+		can6 = (y+1,x) not in E
+		can7 = (y+1,x-1) not in E
+		can8 = (y,x-1) not in E
+		canN = (y-1,x) if can1 and can2 and can3 else None
+		canS = (y+1,x) if can5 and can6 and can7 else None
+		canW = (y,x-1) if can7 and can8 and can1 else None
+		canE = (y,x+1) if can3 and can4 and can5 else None
+		moves = [canN, canS, canW, canE]
+		moves = [moves[(r+0)%4], moves[(r+1)%4], moves[(r+2)%4], moves[(r+3)%4]]
+		if all(m is not None for m in moves):  # far away
+			continue
+		if all(m is None for m in moves):  # all packed
+			continue
+		#moves = [moves[(r+0)%4], moves[(r+1)%4], moves[(r+2)%4], moves[(r+3)%4]]
+		p:Tuple[int,int] = next(filter(lambda m: m is not None ,moves))
+		#p:Tuple[int,int] = next(filter(lambda m: m is not None, (moves[(r+i)%4] for i in (0,1,2,3)) ))
+		if p not in P: # can move
+			P[p] = (y,x)
+		else: # occupied, invalidate move for all
+			P[p] = MARK
+	moved = { v for k,v in P.items() if v != MARK }
+	newpos = { k for k,v in P.items() if v != MARK }
+	if r+1 == 10:
+		(W,H) = dim()
+		print(W, H, W * H - len(E))
+	if len(newpos) == 0:
+		(W,H) = dim()
+		print(f"no move after {r+1}, {W}, {H}")
+		break
+	E = (E - moved) | newpos