advent_of_code_2022

commit 52dd2774d7008095a7e7c39048e874e694ff6153
parent fcb6488ab7d307a0b9316ee8c7fbfc61b17a3687
Author: Eamon Caddigan <eamon.caddigan@gmail.com>
Date:   Wed,  7 Dec 2022 19:13:13 -0800

Solution to day 7, part 2.

Diffstat:
M
src/day_7.jl
 | 
33
++++++++++++++++++++-------------

1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/src/day_7.jl b/src/day_7.jl
@@ -2,26 +2,26 @@
 # https://adventofcode.com/2022/day/7
 using AdventOfCode
 
-example = readlines(IOBuffer("""
-    \$ cd /
-    \$ ls
+example = readlines(IOBuffer(raw"""
+    $ cd /
+    $ ls
     dir a
     14848514 b.txt
     8504156 c.dat
     dir d
-    \$ cd a
-    \$ ls
+    $ cd a
+    $ ls
     dir e
     29116 f
     2557 g
     62596 h.lst
-    \$ cd e
-    \$ ls
+    $ cd e
+    $ ls
     584 i
-    \$ cd ..
-    \$ cd ..
-    \$ cd d
-    \$ ls
+    $ cd ..
+    $ cd ..
+    $ cd d
+    $ ls
     4060174 j
     8033020 d.log
     5626152 d.ext
@@ -120,7 +120,14 @@ end
 @info part_1(input)
 
 function part_2(input)
-    nothing
+    # The total disk space available is 70000000, and we need at least 30000000
+    # available. Find out how much we need to free:
+    fs = build_directory(input)
+    dirsizes = size_directories(fs)
+    needtofree = dirsizes[fs] - (70000000 - 30000000)
+
+    # Find the smallest directory, if deleted, that would free up enough space
+    minimum([x for x in values(dirsizes) if x > needtofree])
 end
-@assert part_2(example) == nothing
+@assert part_2(example) == 24933642
 @info part_2(input)