Function Get-StringHash([String] $String,$HashName = "MD5") { $StringBuilder = New-Object System.Text.StringBuilder [System.Security.Cryptography.HashAlgorithm]::Create($HashName).ComputeHash([System.Text.Encoding]::UTF8.GetBytes($String))|%{ [Void]$StringBuilder.Append($_.ToString("x2")) } $StringBuilder.ToString() } function Get-OpenSeatCount { param ( [int]$seatrow, [int]$seatnum, $seatmap ) # write-host "$(Get-StringHash -String ($seatmap -join ''))" $positionstocheck=@{ 'UpperLeft'=@(($seatrow -1),($seatnum -1)) 'UpperMiddle'=@(($seatrow -1),($seatnum)) 'UpperRight'=@(($seatrow -1),($seatnum +1)) 'Left'=@(($seatrow),($seatnum -1)) 'Right'=@(($seatrow),($seatnum +1)) 'LowerLeft'=@(($seatrow +1),($seatnum -1)) 'LowerMiddle'=@(($seatrow +1),($seatnum)) 'LowerRight'=@(($seatrow +1),($seatnum +1)) } #write-host $positionstocheck #write-host "SEATROW: $seatrow SEATNUM: $seatnum" $adjacentseats="" foreach($position in $positionstocheck.keys){ $thisrow, $thisseat = $positionstocheck[$position] if($thisrow -eq -1){ continue } if($thisrow -gt $seatmap.count -1){ continue } if($thisseat -eq -1){ continue } if($thisseat -gt $seatmap[$seatrow].length -1){ continue } $myposition = $positionstocheck[$position] $row = $myposition[0] #write-host "$row" $seat = $myposition[1] #write-host "$seat" #write-host $seatmap[$row] $myrow = $seatmap[$row].ToCharArray() $adjacentseats += $myrow[$seat] } #write-host $adjacentseats return ($adjacentseats.tochararray()|?{$_ -eq '#'}).count } function proc-Seats(){ param( $seatmap ) $origmap = $seatmap.clone() #$myseatmap= $seatmap.clone() #$myseatmap=$seatmap for($row=0;$row -lt $seatmap.count; $row++){ for($seatnum=0; $seatnum -lt ($seatmap[$row].ToCharArray().count); $seatnum++){ if($seatmap[$row][$seatnum] -ne '.'){ $occupiedseats = Get-OpenSeatCount -seatrow $row -seatnum $seatnum -seatmap $origmap #write-host "Occupied Around $occupiedseats, SEATNUM $seatnum, SEATROW $row" if( $occupiedseats -ge 4){ #write-host $occupiedseats $myrow = $seatmap[$row].tochararray() $myrow[$seatnum]='L' $seatmap[$row]=$myrow -join "" } elseif ($occupiedseats -eq 0) { #write-host $occupiedseats $myrow = $seatmap[$row].tochararray() $myrow[$seatnum]='#' $seatmap[$row]=$myrow -join "" } } } } $seatmap } $seatmap = @(get-content .\aocd11input.txt) #$seatmap=@('L.LL.LL.LL','LLLLLLL.LL','L.L.L..L..','LLLL.LL.LL','L.LL.LL.LL','L.LLLLL.LL','..L.L.....','LLLLLLLLLL','L.LLLLLL.L','L.LLLLL.LL') $repeat=$false $loopnum=0 $optionhashes = @() do{ $maphash =Get-StringHash -String ($seatmap -join '') $loopnum++ write-host "Loop $loopnum" write-host $maphash $seatmap = @(proc-Seats -seatmap $seatmap) $seatmap if($optionhashes -contains $maphash ){ write-host "Repeat detected. Stopping" $repeat=$true } else { $optionhashes += $maphash } #read-host } while ( $repeat -eq $false ) (($seatmap -join "").tochararray()|?{$_ -eq '#'}).count