add day 2 online solution

02_ONLINE_01.awk

@@ -0,0 +1,12 @@
+# from /u/haveo on reddit
+# https://old.reddit.com/r/adventofcode/comments/zac2v2/2022_day_2_solutions/iynf98p/?context=3
+
+{
+	a = index("AB", $1)
+	b = index("XYZ", $2)
+	x += (b-a+4) % 3 * 3 + b
+	y += 3 * b + (a+b) % 3 - 2
+}
+END {
+	print "1: "x" 2: "y
+}

README.md

@@ -2,6 +2,8 @@ my advent of code 2022 solutions
 
 mainly going to be using shell + posix-defined utilities, probably
 
+this repo will also include online solutions that I think are neat, indicated by "ONLINE" and with credit in the file
+
 ## Days
 1. awk (uses features exclusive to GNU's implementation, gawk)
 2. shell (completely POSIX-conforming implementation)