Combined script that provides answers to both parts.

Advent Of Code Day 9-Combined.ps1

@@ -0,0 +1,68 @@
+$inputdata=import-csv -header "Number" .\aocd9input.txt
+$inputdata | %{$_.Number = [int64]$_.Number}
+$buffer=25
+$mynumbers=$inputdata[0 .. 24] | select-object -ExpandProperty Number
+$tolookfor=-1
+for($i=25; $i -lt $inputdata.count; $i++){
+
+    $minval = (($mynumbers|Sort-Object  )[0 .. 1] |measure-object -sum | select-object -ExpandProperty sum)[0]
+    $maxval = (($mynumbers|Sort-Object  )[-2 .. -1] |measure-object -sum | select-object -ExpandProperty sum)[0]
+    $newnum = $inputdata[$i].Number
+    #write-host "Prior $($mynumbers[-1]) : $newnum"
+    if($newnum -lt $minval){
+        #write-host "ERROR $newnum too low"
+        $tolookfor = $newnum
+        break
+    }
+    if($newnum -gt $maxval){
+        #write-host "ERROR $newnum too high"
+        $tolookfor = $newnum
+        break
+    }
+    $possiblevalues = @()
+    for($b=0;$b -lt $mynumbers.Count;$b++){
+        $mynum=$mynumbers[$b]
+        for($a=1;$a -lt $mynumbers.count;$a++ ){
+            $nextnum = $mynumbers[$a]
+            if($mynum -eq $nextnum){
+                #write-host "$mynum is same as $nextnum"
+                continue
+            }
+            $possiblevalues += $mynum + $nextnum
+        }
+    }
+    if($possiblevalues -notcontains $newnum){
+        #write-host "ERROR $newnum not a sum of prior $buffer numbers"
+        $tolookfor = $newnum
+        break
+    }
+    $null,$mynumbers=$mynumbers
+    $mynumbers += $newnum
+}
+$howmanynums=2
+$found=$false
+if($tolookfor -eq -1){
+    throw "Invalid Input for final check"
+}
+write-host "Part 1 Answer is $tolookfor"
+foreach($num in ($howmanynums .. $inputdata.count)){
+    if($found){break}
+    for($i=0;$i -lt $inputdata.count - $num; $i++){
+        if($found){
+            $break
+        }
+        $possiblevalues = @()
+        $mynums = $inputdata[$i .. ($i + $num -1)]|Select-Object -ExpandProperty Number
+        $mysum = $mynums | Measure-Object -sum | Select-Object -ExpandProperty Sum
+        if($mysum -eq $tolookfor){
+            $minnum = ($mynums | Measure-Object -minimum).minimum
+            $maxnum = ($mynums | Measure-Object -Maximum).Maximum
+#            write-host "$mynums sum to $mysum"
+#            write-host "Smallest $minnum + Largest $maxnum = $($minnum + $maxnum)"
+            write-host "Part 2 answer is $($minnum + $maxnum)"
+            $found=$true
+            break
+        }
+        #write-host "$mynums : $mysum"
+    }
+}