advent-of-code/2022
1
0
Fork 0
mirror of https://github.com/parnic/advent-of-code-2022.git synced 2025-06-16 13:40:13 -05:00
Code Issues Packages Projects Releases Wiki Activity

Day 24 optimized

Browse Source 
This takes the runtime from 5-6s on part 2 to ~100ms by using a better data structure for lookups than trying to check if the Queue contains an existing state or not.

Now the slowest thing here is the GetNeighbors loop. I feel like that can be improved somehow, but I'm not sure if I can improve it and still retain its ergonomics or not. We shall see!
This commit is contained in:
Chris Pickett
2022-12-24 14:40:05 -06:00
parent dac99b0e72
commit cc2b166e23
1 changed files with 9 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
src/24.cs
View File

@ -192,6 +192,7 @@ internal class Day24 : Day
private static int getMinSteps(ivec2 start, ivec2 dest, int startGridState = 0) private static int getMinSteps(ivec2 start, ivec2 dest, int startGridState = 0)
{ {
Queue<(ivec2 pos, int steps)> states = new(); Queue<(ivec2 pos, int steps)> states = new();
HashSet<ivec3> visited = new();
states.Enqueue((start, 0)); states.Enqueue((start, 0));
int minSteps = int.MaxValue; int minSteps = int.MaxValue;
@ -208,10 +209,11 @@ internal class Day24 : Day
// check if we can wait // check if we can wait
if (next[q.pos.y][q.pos.x] == (int) cellType.open) if (next[q.pos.y][q.pos.x] == (int) cellType.open)
{ {
var nextState = (pos: q.pos, steps: q.steps + 1); var visitedVec = new ivec3(q.pos.x, q.pos.y, q.steps + 1);
if (!states.Contains(nextState)) if (!visited.Contains(visitedVec))
{ {
states.Enqueue(nextState); states.Enqueue((q.pos, q.steps + 1));
visited.Add(visitedVec);
} }
} }
@ -235,10 +237,11 @@ internal class Day24 : Day
if (next[n.y][n.x] == (int) cellType.open) if (next[n.y][n.x] == (int) cellType.open)
{ {
var nextState = (pos: n, steps: q.steps + 1); var visitedVec = new ivec3(n.x, n.y, q.steps + 1);
if (!states.Contains(nextState)) if (!visited.Contains(visitedVec))
{ {
states.Enqueue(nextState); states.Enqueue((n, q.steps + 1));
visited.Add(visitedVec);
} }
} }
} }