Day 8 Both Stars

Author: Chris Stewart

src/dc/aoc2023/Day8.cls

@@ -0,0 +1,158 @@
+Class doc.aoc2023.Day8 Extends doc.aoc2023.Base
+{
+
+Parameter InputFile = "input8.txt";
+
+ClassMethod Run() As %Integer
+{
+	Kill ^map
+    
+    Set stream=..GetInput(..#InputFile)
+   
+    Set count=0 
+    Set instructions=stream.ReadLine() //store the path here
+    set ^maps = instructions
+    Set null=stream.ReadLine() //There's a blank line, it's hacky but just skip over it
+    //Setup all reference globals
+	While 'stream.AtEnd {
+    
+	    Set line=stream.ReadLine()
+        set node = $P(line," ",1) //first string is node name
+        //cheating ahed, the keys are fixed width, so will just $E them out
+        //this would need to be changed if the keys were variable length
+        //or just a different length.
+        set left = $E(line,8,10)
+        set right = $E(line,13,15)
+        w !,"Node "_node_"  LEFT: "_left_"  RIGHT: "_right
+        set ^maps(node,"L")=left
+        set ^maps(node,"R")=right
+
+    }
+
+    s rank = ""
+    s count =0
+    s accumulator = 0
+    set currentnode = "AAA"
+    for   {
+      
+      
+      s realcount = (count#($L(^maps)))+1
+      s instruction = $E(^maps,realcount)
+      s currentnode =^maps(currentnode,instruction)
+      s count=$I(count)
+      q:currentnode="ZZZ"
+      w !, count,?10,currentnode,?20,instruction,?23,realcount
+      
+    }
+
+     Write !,"returning results: "_count,!
+    Quit count
+}
+
+ClassMethod Run2() As %Integer
+{
+    Kill ^ghostmaps
+    kill ^ghostindex
+    Kill ^foundnodes
+    
+    Set stream=..GetInput(..#InputFile)
+   
+    Set count=0 
+    Set instructions=stream.ReadLine() //store the path here
+    set ^ghostmaps = instructions
+    Set null=stream.ReadLine() //There's a blank line, it's hacky but just skip over it
+    //Setup all reference globals
+	While 'stream.AtEnd {
+    
+	    Set line=stream.ReadLine()
+        set node = $P(line," ",1) //first string is node name
+        if $E(node,3)="A" set ^ghostindex(node)="" //Get all starting points
+        //cheating ahed, the keys are fixed width, so will just $E them out
+        //this would need to be changed if the keys were variable length
+        //or just a different length.
+        set left = $E(line,8,10)
+        set right = $E(line,13,15)
+        w !,"Node "_node_"  LEFT: "_left_"  RIGHT: "_right
+        set ^maps(node,"L")=left
+        set ^maps(node,"R")=right
+
+    }
+
+    s rank = ""
+    s count =0
+    s accumulator = 0
+
+    set aKey = ""
+    set aCount = 0
+    for   {
+        set aKey=$O(^ghostindex(aKey))
+        q:aKey=""
+        d $INCREMENT(aCount)
+
+    }
+    w !,"There are "_aCount_" nodes that start with A (or Z)"
+    
+    set nodekey=""
+    for   {
+        set count = 0
+    set nodekey=$O(^ghostindex(nodekey))
+    quit:nodekey=""
+    w !,"nodekey "_nodekey
+    set startnode=nodekey
+    set currentnode=nodekey
+    for   {
+    
+      s realcount = (count#($L(^maps)))+1
+      s instruction = $E(^maps,realcount)
+      s currentnode =^maps(currentnode,instruction)
+      s count=$I(count)
+      if $E(currentnode,3)="Z" {
+      
+        s ^foundnodes(startnode)=count
+        }
+        q:$DATA(^foundnodes(startnode))
+      
+    }
+    }
+    W !
+    zw ^foundnodes
+    
+    set foundkey=$O(^foundnodes(""))
+    set gcd = ^foundnodes(foundkey)
+    
+    for  {
+        set foundkey=$O(^foundnodes(foundkey))
+        q:foundkey=""
+        set oldgcd=gcd
+        set gcd=..GreatestCommonDivisor(gcd,^foundnodes(foundkey))
+    }
+    w !,"GCD is "_gcd
+    //compare smallest and biggest, and we should be ok?
+    set largekey=$O(^foundnodes("")) //prime the first one
+    set largenumber=^foundnodes(largekey)
+    set lcm = largenumber
+    for  {
+    set largekey=$O(^foundnodes(largekey))
+    quit:largekey=""
+    set largestnumber = ^foundnodes(largekey)
+    w !,"Comparing "_lcm_" and "_largestnumber
+    set lcm = (lcm*largestnumber)/..GreatestCommonDivisor(lcm,largestnumber)
+    }
+    w !,"LCM is "_lcm
+
+     Write !,"returning results: "_count,!
+    Quit count
+}
+
+ClassMethod GreatestCommonDivisor(a, b) As %Integer
+{
+    
+    for    {
+        if a>b {set a = a-b}
+        else {set b = b-a}
+        quit:a=b
+    }
+    quit a
+}
+
+}