From f6ff66ea2da1f30303f17a2dac341411fb325881 Mon Sep 17 00:00:00 2001
From: blenovo <bk@gmail.com>
Date: Sat, 16 Aug 2025 00:38:26 +0200
Subject: final puzzle and little cleanup for 2018

---
 2018/aoc2018-d05.py | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 2018/aoc2018-d05.py

(limited to '2018/aoc2018-d05.py')

diff --git a/2018/aoc2018-d05.py b/2018/aoc2018-d05.py
new file mode 100644
index 0000000..6ebd839
--- /dev/null
+++ b/2018/aoc2018-d05.py
@@ -0,0 +1,64 @@
+#advent of code 2018
+#day 05
+#part 1 and 2
+
+#extremely slow, rewrite candidate
+
+def polymer_d(a,b):
+	return (cdiff == abs(ord(a) - ord(b)));
+
+def polymer_strip(inp):
+	is_poly = True;
+	while is_poly:
+		is_poly = False;
+		for x in range(1,len(inp)):
+			x1 = inp[x-1];
+			x2 = inp[x];
+			if polymer_d(x1,x2):
+				#print((x1+x2));
+				inp = inp.replace((x1+x2),"");
+				#myinput = myinput[
+				is_poly = True;
+				break;
+	return inp;
+
+#part1
+def PolymerReaction(myinput):
+	is_poly = True;
+	while is_poly:
+		is_poly = False;
+		sub = "";
+		for x in range(2,len(myinput)):
+			x1 = myinput[x-2];
+			x2 = myinput[x-1];
+			if polymer_d(x1,x2):
+				myinput = sub + myinput[x:];
+				is_poly = True;
+				break;
+			else:
+				sub += x1;
+	return len(myinput);
+
+#part 2
+def ShortestPolymer(myinput):
+	inp_max = 999999;
+	inp_c = "";
+	for c in range(ord("A"),ord("Z")+1,1):
+		subinput = myinput;
+		subinput = subinput.replace(chr(c),"");
+		subinput = subinput.replace(chr(c+cdiff),"");
+		subinput = polymer_strip(subinput);
+		if (len(subinput) < inp_max):
+			inp_max = len(subinput);
+			inp_c = c;
+	return inp_max
+
+f = open("05.in","r");
+cdiff = 32;
+PuzzleInput = f.read().replace("\n","");
+f.close();
+p1 = PolymerReaction(""+PuzzleInput);
+print("part 1", p1);
+p2 = ShortestPolymer(""+PuzzleInput);
+print("part 2 ",p2);
+
-- 
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