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MatsemannMatsemann
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day23 p2
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‎adventofcode2021/inputs/day23_dummy.txt‎

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,14 @@
1+
#############
2+
#...........#
3+
###B#B#D#A###
4+
#C#A#D#C#
5+
#########
6+
7+
8+
#############
9+
#...........#
10+
###B#B#D#A###
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#D#C#B#A#
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#D#B#A#C#
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#C#A#D#C#
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#########

‎adventofcode2021/src/main/kotlin/com/matsemann/adventofcode2021/Day23.kt‎

Lines changed: 72 additions & 74 deletions
Original file line numberDiff line numberDiff line change
@@ -5,66 +5,60 @@ import kotlin.math.abs
55

66
val hallwayStops = listOf(0, 1, 3, 5, 7, 9, 10)
77
val doors = listOf(2, 4, 6, 8)
8-
val room1 = listOf(11, 12)
9-
val room2 = listOf(13, 14)
10-
val room3 = listOf(15, 16)
11-
val room4 = listOf(17, 18)
8+
val room1 = listOf(11, 12, 13, 14)
9+
val room2 = listOf(21, 22, 23, 24)
10+
val room3 = listOf(31, 32, 33, 34)
11+
val room4 = listOf(41, 42, 43, 44)
1212
val rooms = listOf(room1, room2, room3, room4)
1313
val costs = listOf(1, 10, 100, 1000)
1414

15-
data class State(val positions: List<Int>) {
15+
data class State(val numNumbers: Int, val positions: List<Int>) {
1616

1717
fun isFinished(): Boolean {
18-
return positions[0] in room1
19-
&& positions[1] in room1
20-
&& positions[2] in room2
21-
&& positions[3] in room2
22-
&& positions[4] in room3
23-
&& positions[5] in room3
24-
&& positions[6] in room4
25-
&& positions[7] in room4
18+
return positions.chunked(numNumbers).mapIndexed { i, poses ->
19+
poses.all { it in rooms[i] }
20+
}.all { it }
2621
}
2722

28-
fun getPossibleMoves() : List<Pair<Int, State>> {
23+
fun getPossibleMoves(): List<Pair<Int, State>> {
2924
return positions.indices.flatMap { getMoves(it) }
3025
}
3126

32-
private fun getMoves(amphi: Int) : List<Pair<Int, State>> {
27+
private fun getMoves(amphi: Int): List<Pair<Int, State>> {
3328
val pos = positions[amphi]
34-
val goalRoom = amphi / 2
29+
val goalRoom = amphi / numNumbers
3530
val goalRoomSpots = rooms[goalRoom]
3631

3732
if (pos > 10) { // in a room
38-
// don't make a move if in the correct spot
39-
// if (pos in goalRoomSpots) {
40-
// if (pos == goalRoomSpots[1]) { // In the back, ok
41-
// return listOf()
42-
// } else {
43-
// // In the front, but the one behind is ok
44-
// }
45-
// }
46-
47-
48-
val isInTheBack = pos % 2 == 0
49-
if (isInTheBack) {
50-
val isBlocked = positions.any { it == pos - 1 } // fix for 4
51-
if (isBlocked) {
33+
if (pos in goalRoomSpots) { // don't make a move if in the correct spot
34+
// and nothing behind me that should out
35+
val range = (pos + 1)..((goalRoom + 1) * 10) + numNumbers
36+
val blockedBehind = positions.filterIndexed { i, p -> p in range && i / numNumbers != goalRoom }
37+
if (blockedBehind.isEmpty()) {
5238
return listOf()
5339
}
5440
}
5541

56-
val currentRoom = (pos - 11) / 2
42+
val potentialBlockages = (pos - (pos % 10) + 1) until pos
43+
val isBlocked = positions.any { it in potentialBlockages }
44+
if (isBlocked) { // Can't move out
45+
return listOf()
46+
}
47+
48+
49+
val currentRoom = (pos / 10) - 1
5750
val entrance = doors[currentRoom]
58-
val stepToEntrance = if (isInTheBack) 2 else 1 // fix for 4
51+
val stepToEntrance = pos % 10
5952
val cost = costs[goalRoom]
6053

54+
// move to all possible hallway spots
6155
val moves = hallwayStops.mapNotNull { stop ->
62-
if (canGoTo(to=stop, from=entrance)) {
56+
if (canGoTo(to = stop, from = entrance)) {
6357
val dst = abs(entrance - stop)
6458
val totalCost = cost * (stepToEntrance + dst)
6559
val newState = positions.toMutableList()
6660
newState[amphi] = stop
67-
totalCost to State(newState)
61+
totalCost to State(numNumbers, newState)
6862
} else {
6963
null
7064
}
@@ -78,53 +72,74 @@ data class State(val positions: List<Int>) {
7872
}
7973

8074
val anyoneNotSupposedInTheRoom = positions.filterIndexed { i, amphiPos ->
81-
amphiPos in goalRoomSpots && i / 2 != goalRoom // fix for 4
75+
amphiPos in goalRoomSpots && i / numNumbers != goalRoom
8276
}
83-
84-
if (anyoneNotSupposedInTheRoom.any()) {
77+
if (anyoneNotSupposedInTheRoom.any()) { // Too early to go in
8578
return listOf()
8679
}
8780

88-
val otherIsThereAlready = positions.any {
89-
it in goalRoomSpots
90-
}
81+
val numAlreadyThere = positions.count { it in goalRoomSpots }
9182

92-
val stepsFromEntrance = if (otherIsThereAlready) 1 else 2 // fix for 4
83+
val stepsFromEntrance = numNumbers - numAlreadyThere
9384
val stepsToEntrance = abs(pos - doorPos)
94-
val finalPos = if (otherIsThereAlready) goalRoomSpots[0] else goalRoomSpots[1] // fix for 4
85+
val finalPos = goalRoomSpots[numNumbers - numAlreadyThere - 1]
9586
val cost = costs[goalRoom]
9687

9788
val totalCost = cost * (stepsToEntrance + stepsFromEntrance)
9889

9990
val newState = positions.toMutableList()
10091
newState[amphi] = finalPos
101-
return listOf(totalCost to State(newState))
92+
return listOf(totalCost to State(numNumbers, newState))
10293
}
10394
}
10495

10596
private fun canGoTo(from: Int, to: Int): Boolean {
106-
val range = minOf(from+1, to)..maxOf(from-1, to)
97+
val range = minOf(from + 1, to)..maxOf(from - 1, to)
10798
return !positions.any { pos -> pos in range }
10899
}
109100
}
110101

111102
fun day23_1(lines: List<String>): Any {
103+
// Ex part1
112104
// val startState = listOf(room1[1], room4[1], room1[0], room3[0], room2[0], room3[1], room2[1], room4[0])
113-
val startState = listOf(room2[1], room4[0], room1[0], room2[0], room1[1], room4[1], room3[0], room3[1])
114-
115-
116-
// val startState = listOf(room1[1], room4[1], room1[0], 3, 9, room3[1], room2[1], room4[0])
105+
// val startState = listOf(room1[1], room4[1], room1[0], 3, room2[0], room3[1], room2[1], room4[0])
106+
// val start = State(2, startState)
107+
108+
// Part 1
109+
// val startState = listOf(room2[1], room4[0], room1[0], room2[0], room1[1], room4[1], room3[0], room3[1])
110+
// val start = State(2, startState)
111+
112+
// Ex Part 2
113+
// val startState = listOf(
114+
// room1[3], room3[2], room4[1], room4[3],
115+
// room1[0], room2[2], room3[0], room3[1],
116+
// room2[0], room2[1], room3[3], room4[2],
117+
// room1[1], room1[2], room2[3], room4[0]
118+
// )
119+
// val start = State(4, startState)
120+
121+
// Part 2
122+
val startState = listOf(
123+
room2[3], room3[2], room4[0], room4[1],
124+
room1[0], room2[0], room2[2], room3[1],
125+
room1[3], room2[1], room4[2], room4[3],
126+
room1[1], room1[2], room3[0], room3[3],
127+
)
128+
val start = State(4, startState)
117129

118-
val start = State(startState)
119130

120131
val visited = mutableSetOf<State>()
121132
val queue = PriorityQueue<Pair<Int, State>>(Comparator.comparing { it.first })
122133
queue.offer(0 to start)
123134

135+
var count = 0
136+
124137
while (queue.isNotEmpty()) {
138+
count++
125139
val u = queue.poll()
126140

127141
if (u.second.isFinished()) {
142+
println("Searched: $count")
128143
return u.first
129144
}
130145
if (u.second in visited) {
@@ -138,44 +153,27 @@ fun day23_1(lines: List<String>): Any {
138153
}
139154

140155
}
141-
142-
// val moves = start.getPossibleMoves()
143-
//
144156
return "failed"
145157

146-
// is goal state
147-
148-
// for each amphipod, generate moves
149-
// if inside
150-
// and nothing in front
151-
// move out to all feasible spots
152-
// where feasible is all left/right of entrance not blocked
153-
// costs are moving out + dist from entrance
154-
// if outside, only 0 or 1 move possible
155-
// which is going in, or is blocked
156158
}
157159

158160

159-
fun day23_2(lines: List<String>): Any {
160-
return 2
161-
}
162-
163161
fun main() {
164-
165162
run("1", fileName = "day23_dummy.txt", func = ::day23_1)
166-
// run("1", fileName = "day23_1.txt", func = ::day23_1)
167-
// run("2", fileName = "day23_ex.txt", func = ::day23_2)
168-
// run("2", fileName = "day23_1.txt", func = ::day23_2)
169163
}
170164

171165
/*
172166
OUTPUT
173167
======
174168
175-
Done. Took 27ms to run
176-
Result for 1: 1462
169+
Done. Took 2134ms to run
170+
Result for 1: 11608
171+
Copied to clipboard!
172+
177173
178-
Done. Took 37ms to run
179-
Result for 2: 1497
174+
Searched: 467459
175+
Done. Took 5960ms to run
176+
Result for 1: 46754
177+
Copied to clipboard!
180178
181179
*/

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