11module Day09
22
33using AdventOfCode2024
4+ using StaticArrays
45
56
67function day09 (input:: String = readInput (joinpath (@__DIR__ , " .." " data" " day09.txt"
7- data, filelist, spacelist = parse_data (input)
8- p1 = part1! (copy (data ))
9- p2 = part2! (data )
8+ blocks = parse_input (input)
9+ p1 = part1! (deepcopy (blocks ))
10+ p2 = part2! (blocks )
1011 return [p1, p2]
1112end
1213
13- function parse_data (input)
14- data = Int[]
15- filelist = Tuple{Int,Int}[]
16- spacelist = Tuple{Int,Int}[]
17- id = 0
18- isfile = true
19- index = 1
20- for d ∈ rstrip (input)
21- n = parse (Int, d)
22- if isfile
23- push! (data, (id * ones (Int, n)). .. )
24- push! (filelist, (index, n))
25- id += 1
26- else
27- push! (data, (- 1 * ones (Int, n)). .. )
28- push! (spacelist, (index, n))
29- end
30- isfile = ! isfile
31- index += n
14+ function parse_input (input)
15+ digits = parse .(Int, split (rstrip (input), " "
16+ if length (digits) % 2 == 1
17+ push! (digits, 0 )
3218 end
33- return data, filelist, spacelist
34- end
3519
36- function part1! (data)
37- ispace, inumber = 1 , length (data)
38- while ispace < inumber
39- while ispace < length (data) && data[ispace] != - 1
40- ispace += 1
41- end
42- while inumber > 0 && data[inumber] == - 1
43- inumber -= 1
44- end
45- ispace > inumber && break
46- data[ispace], data[inumber] = data[inumber], data[ispace]
47- ispace += 1
48- inumber -= 1
20+ # start index of block, capacity, used space, original id
21+ disk = Vector {MVector{4,Int}} ()
22+ current_id = 0
23+ current_index = 1
24+ i = 1
25+ while i < length (digits)
26+ push! (disk, (current_index, digits[i] + digits[i+ 1 ], digits[i], current_id))
27+ current_index += digits[i] + digits[i+ 1 ]
28+ current_id += 1
29+ i += 2
4930 end
50- return checksum (data)
31+ return disk
5132end
5233
53- function checksum (data)
54- s, i = 0 , 1
55- while i < length (data)
56- if data[i] == - 1
34+ function part1! (blocks:: Vector{MVector{4,Int}} )
35+ data = generate_disk (blocks)
36+ i, j = 1 , length (blocks)
37+ while i < j
38+ freeindex = blocks[i][1 ] + blocks[i][3 ]
39+ free = blocks[i][2 ] - blocks[i][3 ]
40+ maxtransfer = blocks[j][3 ]
41+ transfer = free >= maxtransfer ? maxtransfer : free
42+ data[freeindex: freeindex+ transfer- 1 ] .= blocks[j][4 ]
43+ data[blocks[j][1 ]+ blocks[j][3 ]- transfer: blocks[j][1 ]+ blocks[j][3 ]- 1 ] .= - 1
44+ blocks[i][3 ] += transfer
45+ blocks[j][3 ] -= transfer
46+ if blocks[i][2 ] == blocks[i][3 ]
5747 i += 1
58- continue
5948 end
60- s += data[i] * (i - 1 )
61- i += 1
49+ if blocks[j][3 ] == 0
50+ j -= 1
51+ end
6252 end
63- return s
53+ return data |> checksum
6454end
6555
66- # TODO : Debug: Why is this wrong?
67- function part2! (data, filelist, spacelist)
68- for (ifilestart, ifilelength) ∈ reverse (filelist)
69- for (i, (ispacestart, ispacelength)) ∈ enumerate (spacelist)
70- if ispacelength >= ifilelength
71- data[ispacestart: ispacestart + ifilelength - 1 ] .= data[ifilestart]
72- data[ifilestart: ifilestart + ifilelength - 1 ] .= - 1
73- spacelist[i] = (ispacestart + ifilelength, ispacelength - ifilelength)
56+ function part2! (blocks:: Vector{MVector{4,Int}} )
57+ data = generate_disk (blocks)
58+ original_usage = [b[3 ] for b ∈ blocks]
59+ for j ∈ reverse (axes (blocks, 1 ))
60+ transfer = original_usage[j]
61+ for i ∈ 1 : j- 1
62+ free = blocks[i][2 ] - blocks[i][3 ]
63+ if free >= transfer
64+ data[blocks[i][1 ]+ blocks[i][3 ]: blocks[i][1 ]+ blocks[i][3 ]+ transfer- 1 ] .= blocks[j][4 ]
65+ data[blocks[j][1 ]: blocks[j][1 ]+ transfer- 1 ] .= - 1
66+ blocks[i][3 ] += transfer
67+ blocks[j][3 ] -= transfer
7468 break
7569 end
7670 end
77- println (string (data))
78- end
79- return checksum (data)
80- end
81-
82- function part2! (data)
83- ifile = length (data)
84- while true
85- ifile, lenfile = prev_file (data, ifile)
86- ifile == 0 && return checksum (data)
87- ispace, lenspace = free_space (data, lenfile, ifile)
88- if ispace == 0
89- ifile -= 1
90- continue
91- else
92- data[ispace: ispace+ lenfile- 1 ] .= data[ifile]
93- data[ifile: ifile+ lenfile- 1 ] .= - 1
94- ifile -= 1
95- end
9671 end
97-
72+ return data |> checksum
9873end
9974
100- function prev_file (data, i)
101- i <= 0 && return 0 , 0
102- if data[i] == - 1
103- while data[i] == - 1
104- if i == 0
105- return 0 , 0
106- end
107- i -= 1
108- end
109- end
110- id = data[i]
111- while i > 0 && data[i] == id
112- i -= 1
75+ function generate_disk (blocks:: Vector{MVector{4,Int}} )
76+ data = - 1 * ones (Int, blocks[end ][1 ] + blocks[end ][2 ] - 1 )
77+ for block ∈ blocks
78+ data[block[1 ]: block[1 ]+ block[3 ]- 1 ] .= block[4 ]
11379 end
114- istart = i + 1
115- iend = istart
116- while iend <= length (data) && data[iend] == data[istart]
117- iend += 1
118- end
119- iend -= 1
120- return istart, iend - istart + 1
80+ return data
12181end
12282
123- function free_space (data, len, imax)
124- free_indices = findall (x -> x == - 1 , data)
125- visited = similar (data, Bool)
126- visited .= false
127- for i ∈ free_indices
128- i >= imax && return 0 , 0
129- visited[i] && continue
130- istart = iend = i
131- while iend <= length (data) && data[iend] == - 1
132- visited[iend] = true
133- iend += 1
83+ function checksum (data:: Vector{Int} )
84+ s, i = 0 , 1
85+ while i < length (data)
86+ if data[i] == - 1
87+ i += 1
88+ continue
13489 end
135- iend -= 1
136- l = iend - istart + 1
137- l >= len && return istart, l
90+ s += data[i] * (i - 1 )
91+ i += 1
13892 end
139- return 0 , 0
93+ return s
14094end
14195
14296end # module
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