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authorNat Lasseter <user@4574.co.uk>2023-12-16 18:35:50 +0000
committerNat Lasseter <user@4574.co.uk>2023-12-16 18:35:50 +0000
commit1a18a179d4679b519b008132fc79a8ba743edca1 (patch)
tree88e19b2a0653bec19555ef134ffd610e448099d7
parent392f5ed69934ea1985fb3f703cc3f9464df1cebc (diff)
Day 16 part 1 but not stupid this time.
-rw-r--r--day16/day16.java73
1 files changed, 44 insertions, 29 deletions
diff --git a/day16/day16.java b/day16/day16.java
index ce07fda..f03dcd6 100644
--- a/day16/day16.java
+++ b/day16/day16.java
@@ -23,12 +23,10 @@ public class day16 {
LinkedList<Beam> beams = new LinkedList<>();
beams.add(new Beam(0, 0, Dir.Right, grid));
- int count = 500000;
- while (beams.size() > 0 && count > 0) {
+ while (beams.size() > 0) {
Beam beam = beams.remove();
LinkedList<Beam> splits = beam.stepThrough();
beams.addAll(splits);
- count -= 1;
}
return Integer.toString(grid.visited());
@@ -56,15 +54,21 @@ public class day16 {
private static class Cell {
Tile tile;
boolean visited;
+ boolean canBlackhole;
public Cell(Tile tile) {
this.tile = tile;
this.visited = false;
+ this.canBlackhole = false;
}
public void visit() {
this.visited = true;
}
+
+ public void doSplit() {
+ this.canBlackhole = true;
+ }
}
private static class Grid {
@@ -145,6 +149,7 @@ public class day16 {
public LinkedList<Beam> stepThrough() {
LinkedList<Beam> splits = new LinkedList<>();
+steppingLoop:
while (!this.escaped()) {
Cell cell = this.grid.cellAt(this.row, this.col);
cell.visit();
@@ -190,35 +195,45 @@ public class day16 {
}
break;
case VSplitter:
- switch (this.dir) {
- case Right:
- case Left:
- splits.add(new Beam(this.row + 1, this.col, Dir.Down, this.grid));
- this.dir = Dir.Up;
- this.row -= 1;
- break;
- case Up:
- this.row -= 1;
- break;
- case Down:
- this.row += 1;
- break;
+ if (!cell.canBlackhole) {
+ switch (this.dir) {
+ case Right:
+ case Left:
+ cell.doSplit();
+ splits.add(new Beam(this.row + 1, this.col, Dir.Down, this.grid));
+ this.dir = Dir.Up;
+ this.row -= 1;
+ break;
+ case Up:
+ this.row -= 1;
+ break;
+ case Down:
+ this.row += 1;
+ break;
+ }
+ } else {
+ break steppingLoop;
}
break;
case HSplitter:
- switch (this.dir) {
- case Right:
- this.col += 1;
- break;
- case Left:
- this.col -= 1;
- break;
- case Up:
- case Down:
- splits.add(new Beam(this.row, this.col + 1, Dir.Right, this.grid));
- this.dir = Dir.Left;
- this.col -= 1;
- break;
+ if (!cell.canBlackhole) {
+ switch (this.dir) {
+ case Right:
+ this.col += 1;
+ break;
+ case Left:
+ this.col -= 1;
+ break;
+ case Up:
+ case Down:
+ cell.doSplit();
+ splits.add(new Beam(this.row, this.col + 1, Dir.Right, this.grid));
+ this.dir = Dir.Left;
+ this.col -= 1;
+ break;
+ }
+ } else {
+ break steppingLoop;
}
break;
default: