empty struct instead of bool for better memory usage

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))
 }