add solution for day 7

src/day_7.jl

@@ -0,0 +1,65 @@
+include(joinpath(readchomp(`git rev-parse --show-toplevel`), "aoc.jl"))
+import .Aoc: @aoc
+
+function size_of_dir(dirs::Dict{String, Int}, subdirs::Dict{String, Array{String}}, dir::String)
+    size = dirs[dir]
+    for sub in subdirs[dir]
+        sub in keys(dirs) && (size += size_of_dir(dirs, subdirs, sub))
+    end
+    size
+end
+
+function join_path(s1, s2)
+    s2 == ".." ? join(split(s1, '/')[begin:end-1], '/') : s1 * '/' * s2
+end
+
+function build_dirs(input::Vector{String})
+    dirs = Dict{String, Int}()
+    subdirs = Dict{String, Array{String}}()
+    pwd = ""
+
+    for i in input
+        if i[1] == '$'
+            cmd = split(i[3:end])
+            if cmd[1] == "cd"
+                pwd = cmd[2] == "/" ?  "/" : join_path(pwd, cmd[2])
+                if pwd ∉ keys(dirs)
+                    dirs[pwd] = 0
+                    subdirs[pwd] = []
+                end
+            end
+        else
+            size, name = split(i)
+            if size == "dir"
+                push!(subdirs[pwd], join_path(pwd, name))
+            else
+                dirs[pwd] += parse(Int, size)
+            end
+        end
+    end
+
+    (dirs, subdirs)
+end
+
+function p1(input::Vector{String})
+    dirs, subdirs = build_dirs(input)
+    total = 0
+    for dir in keys(dirs)
+        size = size_of_dir(dirs, subdirs, dir)
+        size <= 100000 && (total+=size)
+    end
+    total
+end
+
+function p2(input::Vector{String})
+    dirs, subdirs = build_dirs(input)
+    free = 70000000 - size_of_dir(dirs, subdirs, "/")
+    res = 0
+    for dir in keys(dirs)
+        size = size_of_dir(dirs, subdirs, dir)
+        (free + size >= 30000000) && (res == 0 || res > size) && (res=size)
+    end
+    res
+end
+
+@aoc(2022, 7)