Advent of Code 2021 - Day 24 - part 2

2021-12-24-02.ps1

[CmdletBinding()]
param(
    [Parameter()]
    [String]$Path = ".\2021-12-24.txt"
)

$Data = @((Get-Content -Path $Path -Raw) -split 'inp w')

class round {
    [int] $w
    [int] $y
    [int] $x
    [int] $div
}

class pair {
    [int]$w1
    [int]$w2
    [int]$diff
}

$rounds = [System.Collections.ArrayList]::new()
$getX = 

for ($w = 1; $w -lt $Data.Count; $w++) {
    $string = $Data[$w]
    if ($string -match '(?m)^add x (-?\d+)') {
        $x = $Matches[1]
    }
    if ($string -match '(?ms)^add y w\s*add y (-?\d+)') {
        $y = $Matches[1]
    }
    if ($string -match '(?m)^div z (\d+)') {
        $div = $Matches[1]
    }
    $null = $rounds.Add(
        [round]@{
            w = $w
            x = $x
            y = $y
            div = $div
        }
    )
}

$add = [System.Collections.ArrayList]::new()
$pairs = [System.Collections.ArrayList]::new()

foreach ($item in $rounds) {
    if ($item.div -eq 1) {
        $null = $add.Add($item)
    } else {
        $pair = $add[-1]
        $add.Remove($pair)
        $null = $pairs.Add(
            [pair]@{
                w1 = $item.w
                w2 = $pair.w
                diff = - $pair.y - $item.x
            }
        )
    }
}

$serial = [int[]]::new(14)

foreach ($pair in $pairs) {
    if ($pair.diff -lt 0) {
        $serial[$pair.w2 - 1] = 1
        $serial[$pair.w1 - 1] = 1 - $pair.diff
    } else {
        $serial[$pair.w2 - 1] = 1 + $pair.diff
        $serial[$pair.w1 - 1] = 1
    }
}

-join $serial