cleaned up day 8!

12023/08/08.lua

@@ -0,0 +1,69 @@
+io.input("input")
+
+ins = io.read()
+
+_ = io.read()
+
+map = {}
+countA = 0
+countZ = 0
+endA = {}
+for line in io.lines() do
+    node, left, right = line:match("(%a+)[%= %(]+(%a+), (%a+)")
+    map[node] = {L=left, R=right}
+
+    if node:sub(3,3)=="A" then
+        countA=countA+1
+        table.insert(endA, node)
+    end
+end
+
+--part 1
+i = 1
+count = 1
+curr = "AAA"
+repeat
+    step = ins:sub(i,i)
+    sig = map[curr][step]
+    --print(curr, step, ">",sig)
+    if sig~="ZZZ" then
+        i = i==#ins and 1 or i+1
+        count = count + 1
+        curr = sig
+    end
+until sig=="ZZZ"
+print("part 1", count)
+
+--
+--part 2
+i = 1
+count = 1
+curr = {}
+periods = {}
+table.move(endA, 1, #endA, 1, curr)
+repeat
+    step = ins:sub(i,i)
+    sig = {}
+    finZ = true
+    for j, c in ipairs(curr) do
+        s = map[c][step]
+        sig[j] = s
+        if s:sub(3,3)~="Z" then 
+            finZ = false 
+        else
+            --print(c, step,">", s, count)
+            table.insert(periods,count)
+            sig[j] = nil
+        end
+    end
+    if not finZ then
+        i = i==#ins and 1 or i+1
+        count = count + 1
+        curr = {}
+        for j,n in pairs(sig) do
+            table.insert(curr, n)
+        end
+    end
+until finZ
+
+print("part 2: lcm("..table.concat(periods, ",")..")")

12023/08/test

@@ -0,0 +1,9 @@
+RL
+
+AAA = (BBB, CCC)
+BBB = (DDD, EEE)
+CCC = (ZZZ, GGG)
+DDD = (DDD, DDD)
+EEE = (EEE, EEE)
+GGG = (GGG, GGG)
+ZZZ = (ZZZ, ZZZ)

12023/08/test2

@@ -0,0 +1,5 @@
+LLR
+
+AAA = (BBB, BBB)
+BBB = (AAA, ZZZ)
+ZZZ = (ZZZ, ZZZ)

12023/08/test3

@@ -0,0 +1,10 @@
+LR
+
+aaA = (aaB, XXX)
+aaB = (XXX, aaZ)
+aaZ = (aaB, XXX)
+bbA = (bbB, XXX)
+bbB = (bbC, bbC)
+bbC = (bbZ, bbZ)
+bbZ = (bbB, bbB)
+XXX = (XXX, XXX)