From: Skullheadx <admonty1@gmail.com>
Date: Thu, 9 Feb 2023 03:18:12 +0000 (-0500)
Subject: Update S4.py
X-Git-Url: http://git.skullheadx.com/projects/tech/static/gitweb.js?a=commitdiff_plain;h=90565cc57e5a3e8da545383ff409e8447c1d08a2;p=CCC.git

Update S4.py
---

diff --git a/Main/Python/2021/S4.py b/Main/Python/2021/S4.py
index 98cf4be..344b392 100644
--- a/Main/Python/2021/S4.py
+++ b/Main/Python/2021/S4.py
@@ -7,7 +7,7 @@
 #
 # Every day (D is total days), station X and Y swap
 #
-#
+# only want to get off the subway once
 #
 # """
 from queue import Queue
@@ -27,39 +27,32 @@ stations = list(map(int, input().split()))
 
 for i in range(D):
 	X, Y = tuple(map(int, input().split()))
-	swap(X-1, Y-1)
-
-
+	swap(X - 1, Y - 1)
 
 	q = Queue()
 	q.put((0, 1))
 
-
-
 	visited = set()
 
 	while not q.empty():
 		m, station = q.get()
 
-		if (m, station) in visited:
-			continue
-		visited.add((m, station))
-
 		if m > len(stations):
-			continue
+			break
 
 		if station == N:
 			print(m)
 			break
-		# print(f"q:{q.qsize()}")
+
+
+		# take a train
+		if stations[m] == station:
+			q.put((m + 1, stations[m + 1]))
 
 		# take a walkway
+		if station in visited:
+			continue
+		visited.add(station)
 		if station in walkways:
 			for destination in walkways[station]:
 				q.put((m + 1, destination))
-
-		# take a train
-		if stations[m] == station and m + 1 < len(stations):
-			q.put((m + 1, stations[m + 1]))
-		# wait at the station
-		q.put((m + 1, station))