aoc2022-day7

# Step 1 : preprocess the input

f = open("input.txt")
insts = f.readlines()

processed = []
for i in insts:
    if i.startswith("$ cd /"):
        processed.append("cd /home/ey3ball/projects/2022/fs/\n")
    elif i.startswith("$ ls"):
        pass
    elif i.startswith("$ cd"):
        processed.append(i.replace("$ cd", "cd"))
    elif i.startswith("dir"):
        processed.append(i.replace("dir", "mkdir"))
    else:
        processed.append("truncate -s " + i)

f = open("output.sh", "w+")
f.writelines(processed)

# Step 2 : run the script

./output.sh

# Step 3 : solve part 1

#!/bin/bash

cd fs

total=0
find  . -mindepth 1 -type d | xargs -l1 du -sb | while read line; do
    size=$(echo "$line" | cut -f1)
    dir=$(echo "$line" | cut -f2)
    adjust=$(( $(find $dir -type d | wc -l) * 4096))
    actual=$(($size - $adjust))

    if [ $actual -lt 100000 ]; then
        total=$(( $total + $actual ))
        echo $total
    fi
done

Step 4 : solve part 2

$ du -sb .
45150876
$ find . -type d | wc -l
189
# 70000000 - (45150876−189×4096) = 25623268
# 30000000−25623268 = 4376732
# == target size of directory to remove
$ find  . -mindepth 1 -type d | xargs -l1 du -sb | sort -n
...
4226349	./qfrrtb/pnrdwlqn/zcj/vpqvpmv/tzr
4505354	./pjsd/wtwhzzwz/wglhbp
5824348	./pjsd/wtwhzzwz/dgqljsbq
...
# looks like ./pjsd/wtwhzzwz/wglhbp will work
$ find  ./pjsd/wtwhzzwz/wglhbp  -type d  | wc -l
15
# solution = 4505354 - 15 * 4096