From c09e706d42d644f48d99a80a332e8b72676aa67c Mon Sep 17 00:00:00 2001
From: David Ashby <delta.mu.alpha@gmail.com>
Date: Sun, 12 Dec 2021 13:29:41 -0500
Subject: [PATCH] empty struct instead of bool for better memory usage

---
 12/main.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/12/main.go b/12/main.go
index 702711b..be73e21 100644
--- a/12/main.go
+++ b/12/main.go
@@ -63,10 +63,10 @@ func doubleSmallAlready(visitedRooms []string) bool {
 	return false
 }
 
-func descend(rooms map[string]room, currentRoom string, path []string, success chan bool, canVisitSmallRoomTwice bool) {
+func descend(rooms map[string]room, currentRoom string, path []string, success chan struct{}, canVisitSmallRoomTwice bool) {
 	var wg sync.WaitGroup
 	if currentRoom == "end" {
-		success <- true
+		success <- struct{}{}
 		return
 	}
 	for _, link := range rooms[currentRoom].links {
@@ -107,10 +107,11 @@ func partOne() {
 		rooms[p[0]] = a
 		rooms[p[1]] = b
 	}
-	successes := make(chan bool, 10000)
+	successes := make(chan struct{}, 10000)
 	descend(rooms, "start", []string{}, successes, false)
 	fmt.Printf("%+v\n", len(successes))
 }
+
 func partTwo() {
 	scanner := makeScanner(false)
 
@@ -133,7 +134,7 @@ func partTwo() {
 		rooms[p[0]] = a
 		rooms[p[1]] = b
 	}
-	successes := make(chan bool, 200000)
+	successes := make(chan struct{}, 200000)
 	descend(rooms, "start", []string{}, successes, true)
 	fmt.Printf("%+v\n", len(successes))
 }