day 23 python part 2

day23/sol.py

@@ -35,9 +35,9 @@ def neighbors(pos):
 
 def migrate(start, rounds):
     moves = ['N', 'S', 'W', 'E']
-    for _ in range(rounds):
-        show(start)
-        print("-")
+    for i in range(rounds):
+        #show(start)
+        #print("-")
         propose = {}
         destCount = Counter()
 
@@ -52,15 +52,20 @@ def migrate(start, rounds):
                         break
 
         next = {}
+        moved = 0
         for p, d in propose.items():
             if destCount[d] <= 1:
                 next[d] = 1
+                moved += p != d
             else:
                 next[p] = 1
 
+        if not moved:
+            break
+
         moves.append(moves.pop(0))
         start = next
-    return start
+    return start, i+1
 
 def show(pos):
     xmin = min(x for x,y in pos)
@@ -80,5 +85,8 @@ def count_empty(pos):
 
 
 #print(pos)
-n = count_empty(migrate(pos, 10))
+end, _ = migrate(pos, 10)
+print(count_empty(end))
+
+_, n = migrate(pos, 100000)
 print(n)