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Day 10 part 2

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This commit is contained in:
Smaug123
2023-12-10 13:28:33 +00:00
parent 6134ce3f82
commit b6de2b4688
3 changed files with 179 additions and 3 deletions
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178
AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day10.fs
View File

@@ -129,5 +129,181 @@ module Day10 =
distance
let floodFill (stackBuf : ResizeArray<_>) (s : Arr2D<byte>) (currX : int) (currY : int) =
stackBuf.Clear ()
stackBuf.Add (currX, currY)
while stackBuf.Count > 0 do
let currX, currY = stackBuf.[stackBuf.Count - 1]
stackBuf.RemoveAt (stackBuf.Count - 1)
if currX > 0 then
if Arr2D.get s (currX - 1) currY = 0uy then
Arr2D.set s (currX - 1) currY 2uy
stackBuf.Add ((currX - 1, currY))
if currX < s.Width - 1 then
if Arr2D.get s (currX + 1) currY = 0uy then
Arr2D.set s (currX + 1) currY 2uy
stackBuf.Add ((currX + 1, currY))
if currY > 0 then
if Arr2D.get s currX (currY - 1) = 0uy then
Arr2D.set s currX (currY - 1) 2uy
stackBuf.Add ((currX, currY - 1))
if currY < s.Height - 1 then
if Arr2D.get s currX (currY + 1) = 0uy then
Arr2D.set s currX (currY + 1) 2uy
stackBuf.Add ((currX, currY + 1))
let print (s : Arr2D<byte>) =
for y = 0 to s.Height - 1 do
for x = 0 to s.Width - 1 do
match Arr2D.get s x y with
| 0uy -> printf " "
| 1uy -> printf "#"
| 2uy -> printf "."
| s -> failwithf "unrecognised: %i" s
printfn ""
printfn ""
printfn ""
let inline setAt (arr : Arr2D<byte>) (x : int) (y : int) (matching : char) (target : byte) =
Arr2D.set arr x y target
match matching with
| '-' ->
Arr2D.set arr (x - 1) y target
Arr2D.set arr (x + 1) y target
| '|' ->
Arr2D.set arr x (y - 1) target
Arr2D.set arr x (y + 1) target
| 'L' ->
Arr2D.set arr x (y - 1) target
Arr2D.set arr (x + 1) y target
| 'J' ->
Arr2D.set arr x (y - 1) target
Arr2D.set arr (x - 1) y target
| '7' ->
Arr2D.set arr x (y + 1) target
Arr2D.set arr (x - 1) y target
| 'F' ->
Arr2D.set arr x (y + 1) target
Arr2D.set arr (x + 1) y target
| c -> failwithf "bad char: %c" c
let part2 (s : string) =
0
let s = s.AsSpan()
let lineCount = s.Count '\n'
let lineLength = (s.IndexOf '\n' + 1)
let startPos = s.IndexOf 'S'
let buffer = Array.zeroCreate (lineCount * lineLength * 9)
#if DEBUG
let system : Arr2D<byte> =
{
Elements = buffer
Width = 3 * lineLength
}
#else
use ptr = fixed buffer
let system : Arr2D<byte> =
{ Elements = ptr
Length = buffer.Length
Width = 3 * lineLength
}
#endif
let struct (startLine, startCol) = toRowAndCol lineLength lineCount startPos
let mutable prevPointA = startPos
let mutable prevPointB = startPos
Arr2D.set system (3 * startCol + 1) (3 * startLine + 1) 1uy
let mutable pointA =
let pos = ofRowAndCol lineLength lineCount startLine (startCol - 1)
match if pos >= 0 then s.[pos] else 'n' with
| '-'
| 'L'
| 'F' ->
Arr2D.set system (3 * startCol) (3 * startLine + 1) 1uy
pos
| _ ->
let pos = ofRowAndCol lineLength lineCount startLine (startCol + 1)
match if pos < s.Length then s.[pos] else 'n' with
| '-'
| 'J'
| '7' ->
Arr2D.set system (3 * startCol + 2) (3 * startLine + 1) 1uy
pos
| _ ->
Arr2D.set system (3 * startCol) (3 * startLine) 1uy
Arr2D.set system (3 * startCol) (3 * startLine + 2) 1uy
ofRowAndCol lineLength lineCount (startLine + 1) startCol
let mutable pointB =
let pos = ofRowAndCol lineLength lineCount (startLine - 1) startCol
match if pos >= 0 then s.[pos] else 'n' with
| '|'
| '7'
| 'F' ->
Arr2D.set system (3 * startCol + 1) (3 * startLine) 1uy
pos
| _ ->
let pos = ofRowAndCol lineLength lineCount (startLine + 1) startCol
match if pos < s.Length then s.[pos] else 'n' with
| '|'
| 'L'
| 'J' ->
Arr2D.set system (3 * startCol + 1) (3 * startLine + 2) 1uy
pos
| _ ->
let pos = ofRowAndCol lineLength lineCount startLine (startCol + 1)
match if pos < s.Length then s.[pos] else 'n' with
| '-'
| 'J'
| '7' ->
Arr2D.set system (3 * startCol + 2) (3 * startLine + 1) 1uy
pos
| _ ->
ofRowAndCol lineLength lineCount startLine (startCol - 1)
do
let struct (row, col) = toRowAndCol lineLength lineCount pointA
setAt system (3 * col + 1) (3 * row + 1) s.[pointA] 1uy
do
let struct (row, col) = toRowAndCol lineLength lineCount pointB
setAt system (3 * col + 1) (3 * row + 1) s.[pointB] 1uy
while pointA <> pointB do
let currentA = pointA
pointA <- nextPoint s lineLength lineCount pointA prevPointA
prevPointA <- currentA
do
let struct (row, col) = toRowAndCol lineLength lineCount pointA
setAt system (3 * col + 1) (3 * row + 1) s.[pointA] 1uy
let currentB = pointB
pointB <- nextPoint s lineLength lineCount pointB prevPointB
prevPointB <- currentB
do
let struct (row, col) = toRowAndCol lineLength lineCount pointB
setAt system (3 * col + 1) (3 * row + 1) s.[pointB] 1uy
let stackBuf = ResizeArray ()
for line = 0 to system.Height - 1 do
floodFill stackBuf system 0 line
floodFill stackBuf system (system.Width - 1) line
for col = 0 to system.Width - 1 do
floodFill stackBuf system col 0
floodFill stackBuf system col (system.Height - 1)
let mutable answer = 0
for row = 0 to lineCount - 1 do
for col = 0 to lineLength - 1 do
if Arr2D.get system (3 * col + 1) (3 * row + 1) = 0uy then
answer <- answer + 1
answer

2
AdventOfCode2023.FSharp/Test/Test.fsproj
View File

@@ -31,7 +31,7 @@
<EmbeddedResource Include="samples\day8.txt"/>
<EmbeddedResource Include="samples\day9.txt"/>
<EmbeddedResource Include="samples\day10part1.txt" />
<Content Include="samples\day10.txt" />
<EmbeddedResource Include="samples\day10.txt" />
</ItemGroup>
<ItemGroup>

2
AdventOfCode2023.FSharp/Test/TestDay10.fs
View File

@@ -99,4 +99,4 @@ L--J.L7...LJS7F-7L7.
Assert.Inconclusive ()
failwith "unreachable"
Day10.part2 s |> shouldEqual -1
Day10.part2 s |> shouldEqual 393