day 07 - original solution

07.sh

@@ -0,0 +1,59 @@
+#!/bin/sh
+set -euf
+
+# I highly recommend you run this in a ramfs like /tmp
+
+mkdir 07_sol && cd 07_sol
+ROOT="$PWD"
+while read -r line; do
+	set -- $line
+	if [ "$1" = "$" ]; then
+		[ "$2" = "cd" ] && shift && $@
+		continue
+	fi
+	if [ "$1" = "dir" ]; then
+		shift
+		mkdir -p "$*"
+		continue
+	fi
+	dd if=/dev/zero of="$2" bs=1 count="$1"
+done <<-EOF
+	$(sed "s|cd /|cd $ROOT|g" ../07_input)
+EOF
+
+cd "$ROOT"
+
+# used for part 2 later
+used_space=0
+while read -r file; do
+	size="$(wc -c "$file")"
+	used_space=$((used_space + ${size%% *}))
+done <<-EOF
+		$(find -type f)
+	EOF
+needed_space=$((used_space - 40000000))
+
+# I had to do the wc -c thing because the 4kb size inherent to directories got in the way
+
+total_under=0
+minsize=$used_space # minimum size dir > needed space but < prev min dir
+while read -r path; do
+	dirsize=0
+	while read -r file; do
+		size="$(wc -c "$file")"
+		dirsize=$((dirsize + ${size%% *}))
+	done <<-EOF
+			$(find "$path" -type f)
+		EOF
+	if [ $dirsize -le 100000 ]; then
+		total_under=$((total_under + dirsize))
+	fi
+	if [ $dirsize -le $minsize ] && [ $dirsize -ge $needed_space ]; then
+		minsize=$dirsize
+	fi
+done <<-EOF
+		$(find -type d)
+	EOF
+
+printf "PART 1: %s\n" "$total_under"
+printf "PART 2: %s\n" "$minsize"

README.md

@@ -1,14 +1,16 @@
 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
 
+all awk and shell solutions conform to POSIX unless otherwise specified. all c solutions use only the glibc standard library unless otherwise specified (and hopefully only use POSIX functions? idk).
+
 ## Days
 1. awk (GNU gawk)
-2. shell (POSIX)
-3. awk (POSIX)
-4. shell (POSIX)
-5. shell (POSIX; modified input, see 05_i2. could easily be adapted to not rely on it though)
+2. shell
+3. awk
+4. shell
+5. shell (modified input, see 05_i2. could easily be adapted to not rely on it though)
     - I also started work on a "general-case" C solution, but it's currently incomplete
 6. C
+7. shell
+    - this solution literally emulates the entire directory structure as a whole, which I find really funny. it's probably my favorite solution