Day04
Setup
input = """
93,49,16,88,4,92,23,38,44,98,97,8,5,69,41,70,19,11,29,40,90,43,79,96,68,10,31,35,34,32,0,67,83,33,2,76,24,87,99,77,82,66,12,15,28,59,64,95,91,71,62,22,53,46,39,81,75,86,74,56,50,18,17,73,13,54,60,48,21,51,52,55,85,80,30,36,47,3,26,57,84,25,63,27,37,94,7,45,58,9,78,65,72,6,14,61,20,1,42,89
83 11 47 61 45
30 74 73 14 66
53 52 10 57 15
64 50 54 28 87
26 85 63 25 86
72 4 62 30 49
43 93 39 63 25
18 70 44 77 38
84 8 85 5 26
54 50 40 75 2
70 78 55 26 35
75 44 80 15 34
67 47 53 10 56
73 46 27 38 13
64 92 39 87 23
24 66 11 44 51
32 37 83 69 85
46 59 14 99 76
71 28 94 35 98
16 40 74 80 6
1 55 42 59 70
87 81 68 83 56
12 21 20 49 84
89 92 94 2 76
5 17 77 3 32
66 98 10 53 78
80 92 26 38 29
46 34 22 51 8
43 89 87 64 17
63 86 84 62 15
75 65 96 19 87
12 51 97 68 8
42 90 61 10 71
69 48 7 15 26
43 89 21 16 35
64 92 83 2 48
11 34 98 75 96
21 6 54 78 68
42 19 16 41 8
24 58 45 81 49
59 37 46 1 30
51 6 10 44 82
85 3 27 83 96
48 81 56 34 55
35 99 67 12 78
14 49 41 82 78
8 70 29 72 32
61 16 19 68 38
93 46 48 42 31
45 36 84 54 11
96 14 1 71 91
3 89 59 27 2
34 37 5 31 0
22 44 98 43 32
6 66 95 40 46
75 57 76 50 84
32 59 35 12 86
81 77 42 13 21
91 3 9 44 96
4 52 23 18 37
16 62 40 8 82
43 70 29 63 9
41 73 77 13 59
44 0 49 53 76
84 55 36 56 48
81 62 35 65 43
6 84 67 44 48
31 56 73 69 33
66 92 40 77 55
4 70 97 88 13
63 5 12 66 77
68 74 15 84 16
1 45 72 54 42
58 33 35 65 21
73 60 67 10 95
0 25 16 42 45
27 98 87 29 3
62 6 88 19 95
84 33 53 89 37
46 38 97 96 77
98 62 8 73 20
81 83 51 55 21
4 13 70 60 1
32 82 12 22 61
79 40 92 76 36
91 52 17 13 76
25 79 88 90 87
41 58 89 30 66
56 49 69 35 61
44 57 81 34 43
69 88 87 72 84
36 55 13 11 27
47 40 34 99 38
23 18 96 57 28
41 67 26 6 54
39 69 49 40 86
6 75 90 31 21
82 15 48 37 88
55 23 4 7 10
68 81 87 56 73
41 65 82 20 31
42 22 88 70 75
73 76 54 15 83
67 99 46 28 72
9 51 57 96 38
3 1 15 13 79
7 94 77 86 30
54 39 9 5 43
66 34 92 87 88
59 93 32 48 51
98 21 19 76 97
93 83 5 24 99
14 80 85 7 92
8 53 1 78 72
45 20 2 13 6
51 28 54 62 42
97 70 77 23 81
15 67 33 55 0
35 78 14 61 8
26 13 99 56 24
71 99 2 72 21
22 54 30 38 41
92 47 56 70 34
28 90 0 67 78
63 14 84 97 61
86 81 85 21 65
59 47 56 28 32
89 54 44 71 1
80 55 76 12 33
13 11 31 92 88
54 41 8 46 83
35 2 23 15 52
31 91 92 61 19
25 17 98 53 22
72 78 81 84 27
61 72 95 50 49
19 37 85 64 71
78 18 59 54 67
75 68 27 90 1
8 62 3 32 83
0 20 88 30 52
87 13 73 3 79
37 22 10 70 67
61 48 81 40 54
50 68 93 8 34
88 39 9 36 15
14 79 1 58 83
4 73 42 55 37
0 53 77 28 8
18 92 21 25 62
65 36 59 80 97
6 60 3 95 52
20 10 78 1 46
45 26 38 96 25
37 85 19 98 75
27 47 38 62 86
16 35 87 46 74
52 94 25 9 2
61 88 51 90 68
79 72 1 20 82
5 29 9 44 64
89 15 78 56 2
85 93 28 79 34
87 16 21 59 49
8 39 71 57 75
0 64 99 62 28
47 3 87 31 9
70 10 97 24 91
65 43 96 86 85
35 88 25 67 83
69 67 8 31 49
57 22 83 56 79
91 54 70 33 53
68 47 84 80 35
21 7 65 4 17
4 2 18 62 13
74 31 60 59 16
71 43 86 17 93
70 81 50 53 64
51 96 49 7 47
51 96 12 23 18
27 2 35 55 50
92 44 4 49 85
40 58 6 13 16
98 5 48 74 57
88 3 15 45 95
59 2 58 98 77
62 89 80 11 74
10 49 48 72 76
86 61 53 60 44
77 85 1 3 76
94 30 83 6 39
80 92 24 31 46
64 47 65 7 84
23 86 79 82 34
99 5 2 23 53
78 79 55 96 84
91 43 47 69 63
80 29 94 14 32
1 18 90 28 68
29 51 43 17 0
4 44 48 93 40
52 11 75 50 88
34 95 47 68 55
84 54 19 12 5
26 98 34 92 53
80 69 68 5 71
1 30 61 15 56
96 22 52 70 25
93 7 36 18 55
19 16 4 32 55
61 66 67 50 88
89 51 64 57 43
87 31 49 85 9
90 39 56 96 59
25 59 57 10 52
8 50 28 71 3
99 78 47 31 42
0 82 98 93 2
89 81 55 76 13
19 81 93 25 20
87 70 42 38 44
33 98 62 91 39
49 80 47 56 28
92 46 8 78 75
70 86 32 10 83
30 62 99 45 88
6 5 43 22 16
57 48 49 18 68
33 28 80 94 9
85 65 83 59 44
52 24 87 31 56
17 94 73 43 58
10 23 46 36 89
53 28 63 62 70
72 7 99 40 77
68 71 12 19 97
54 73 64 43 11
44 29 58 75 78
21 6 30 90 28
97 32 21 48 25
67 58 64 0 1
50 49 27 70 43
76 22 12 51 37
93 20 62 36 26
76 69 52 2 67
13 18 1 62 81
94 43 99 10 45
17 55 19 44 78
46 3 16 74 73
23 17 66 2 78
44 53 67 19 69
94 43 85 34 14
26 63 40 1 27
95 48 20 72 64
49 96 17 42 53
8 15 62 3 90
9 57 61 82 46
95 44 75 27 23
10 6 24 63 98
80 35 65 55 37
64 91 77 3 94
46 24 97 87 78
60 2 61 23 32
51 92 59 73 25
68 5 32 99 70
18 43 96 63 52
88 3 59 76 25
65 48 72 2 24
67 41 60 44 87
12 48 72 86 93
27 36 96 51 21
2 50 34 83 6
49 65 32 42 87
88 10 43 84 22
78 70 44 10 80
18 71 17 50 27
12 46 88 6 91
98 0 31 85 56
92 53 72 77 28
85 84 6 89 24
15 41 21 92 71
88 90 95 32 98
46 60 35 38 17
36 66 93 70 40
54 5 41 59 76
38 47 48 51 71
80 96 39 85 0
68 61 55 40 13
78 94 99 19 30
50 3 55 37 25
16 59 48 52 13
41 20 46 27 39
90 80 30 84 93
22 12 79 74 0
16 97 4 58 80
68 49 0 87 35
88 63 1 36 74
45 91 55 46 75
22 17 43 19 71
30 98 31 63 16
62 6 3 9 67
61 11 29 66 52
80 97 42 72 76
78 57 90 13 89
40 22 8 11 43
90 61 29 10 88
69 86 74 26 70
14 51 93 32 80
84 75 81 72 16
91 22 89 72 82
63 58 80 42 45
11 40 29 41 90
17 16 62 14 35
23 4 65 79 0
32 76 30 8 90
0 89 1 95 48
40 44 68 49 37
35 26 81 51 21
47 19 83 91 71
9 31 70 42 16
82 4 84 54 45
58 36 53 20 44
26 5 69 90 52
95 67 51 7 76
5 64 51 63 8
80 22 85 35 16
31 99 68 53 65
58 2 32 83 59
92 93 18 56 62
32 94 9 68 79
26 34 7 1 0
95 56 69 29 20
18 55 25 15 88
54 97 61 51 10
25 9 1 70 80
14 75 58 30 81
45 19 2 41 95
93 21 74 7 59
34 89 52 78 54
81 1 61 92 51
97 35 3 7 39
76 62 32 26 90
71 72 19 31 15
45 57 82 14 24
66 6 27 11 81
40 60 48 75 91
86 31 62 36 72
54 76 25 44 74
84 29 20 53 68
80 33 97 7 51
74 66 6 67 83
76 68 87 90 91
2 53 49 31 82
72 95 26 28 22
33 1 93 2 8
7 19 6 51 47
63 68 26 90 54
59 22 9 46 28
40 20 80 86 15
47 5 23 64 31
54 44 51 14 21
24 25 93 62 0
41 15 56 91 40
48 17 69 11 81
59 27 47 82 44
78 89 34 1 23
31 91 35 30 52
48 15 32 43 5
42 41 12 53 77
83 8 74 12 4
45 56 22 68 50
99 2 55 62 90
36 14 3 33 93
43 26 85 96 61
13 33 85 32 84
41 66 48 9 11
70 80 45 82 34
74 94 67 58 98
89 8 39 51 64
20 23 32 57 52
17 7 86 90 75
78 44 43 41 12
29 92 0 35 48
15 61 42 74 21
76 92 73 16 2
78 18 91 86 51
70 66 11 12 79
44 28 49 56 80
64 74 67 46 20
56 87 96 62 53
63 7 47 39 66
61 78 23 33 10
65 76 19 3 94
25 84 90 68 79
33 79 70 88 61
99 23 76 37 66
16 81 67 46 49
91 73 83 44 18
28 59 85 55 21
15 44 70 23 43
94 48 8 77 28
53 63 17 83 69
25 74 40 11 35
78 36 31 85 84
73 80 31 90 20
53 60 1 87 33
51 89 47 32 22
71 15 55 26 5
77 81 39 11 94
2 15 79 22 50
63 8 66 53 13
26 4 16 20 59
47 93 80 77 38
7 52 92 74 99
68 10 22 61 7
50 63 93 27 54
32 79 20 62 88
13 77 64 89 65
97 41 39 38 75
81 29 64 14 80
25 57 94 13 60
58 33 63 98 42
46 10 17 76 61
2 1 68 56 45
49 23 82 10 56
71 25 85 26 58
65 37 88 7 3
34 80 66 63 74
57 51 35 39 91
35 48 3 22 38
49 19 71 55 62
34 96 69 32 58
40 81 56 36 50
15 52 46 53 90
25 5 93 72 26
88 84 75 87 34
69 60 79 48 50
27 73 33 55 47
65 62 74 46 4
86 82 78 17 16
72 36 76 20 68
69 95 58 37 80
92 97 28 30 7
6 15 8 57 54
50 64 61 0 66
33 44 46 16 17
85 67 76 30 28
25 69 82 54 2
24 96 5 68 6
7 98 31 2 11
13 92 4 72 73
62 29 15 47 40
21 90 57 89 76
81 66 88 12 82
37 45 19 78 73
82 68 96 26 51
35 28 13 12 98
40 47 59 10 18
3 88 6 69 29
62 45 2 46 90
52 25 50 13 1
64 47 73 54 79
33 36 92 15 77
28 4 83 63 5
72 63 57 95 16
17 70 48 23 39
65 96 87 85 33
75 81 82 64 19
80 66 5 58 83
19 9 40 16 33
51 87 66 59 49
94 61 83 81 2
84 27 63 54 10
8 95 88 42 6
4 37 62 80 10
35 98 27 93 69
96 43 65 90 1
23 60 53 44 99
28 38 68 17 71
61 45 93 95 91
35 43 76 98 41
89 21 87 23 99
8 81 58 12 0
32 24 15 70 96
91 59 26 69 61
16 2 45 34 66
95 62 78 82 12
98 41 30 49 50
32 22 53 8 7
94 50 23 64 46
90 19 68 93 76
63 49 9 44 89
83 88 36 55 6
22 14 85 58 70
89 97 86 21 4
57 29 17 46 22
25 10 49 74 63
24 23 93 56 11
37 48 82 55 88
"""
Part a
defmodule Day04a do
def clean_board(board) do
board
|> Enum.map(&String.split(&1, " ", trim: true))
end
# the transpose function
def pivot_board(board) do
board
|> Enum.zip()
|> Enum.map(&Tuple.to_list/1)
end
def winning_board?(board) do
board |> Enum.member?([])
end
def score_winner({current_number, winning_board}) do
winning_board
|> Enum.at(0)
|> Enum.map(fn list -> list |> Enum.map(&String.to_integer/1) end)
|> Enum.map(fn list -> list |> Enum.sum() end)
|> Enum.sum()
|> then(&(&1 * String.to_integer(current_number)))
end
def solve_all_boards_until_winner(boards, numbers) do
solve_all_boards_until_winner(boards, numbers, nil)
end
defp solve_all_boards_until_winner(boards, numbers, nil) do
[current_number | rest_of_numbers] = numbers
# IO.puts("Drawing: " <> current_number)
new_boards = boards |> solve_all_boards_for_one_number(current_number)
winning_board =
new_boards
|> Enum.filter(&winning_board?/1)
if winning_board == [] do
solve_all_boards_until_winner(new_boards, rest_of_numbers, nil)
else
{current_number, winning_board}
end
end
defp solve_all_boards_for_one_number(boards, number) do
boards
|> Enum.map(&solve_for_board(&1, number))
end
def solve_for_board(board, number) do
board |> Enum.map(&solve_for_row(&1, number))
end
def solve_for_row(combination, number) do
solve_for_row(combination, number, [])
end
defp solve_for_row([], _number, result), do: result
defp solve_for_row(combination, number, result) do
[head | tail] = combination
if head == number do
solve_for_row(tail, number, result)
else
solve_for_row(tail, number, [head | result])
end
end
end
[raw_numbers | boards] =
input
|> String.split("\n\n")
numbers =
raw_numbers
|> String.split(",", trim: true)
clean_boards =
boards
|> Enum.map(&String.split(&1, "\n", trim: true))
|> Enum.map(&Day04a.clean_board/1)
boards_with_all_combinations = clean_boards ++ (clean_boards |> Enum.map(&Day04a.pivot_board/1))
boards_with_all_combinations
|> Day04a.solve_all_boards_until_winner(numbers)
|> Day04a.score_winner()
Part b
defmodule Day04b do
def winning_board?(board) do
{cols, rows} = board
cols |> Enum.member?([]) or rows |> Enum.member?([]) or cols == [] or rows == []
end
def score_winner({current_number, winning_board}) do
winning_board
|> Enum.at(0)
|> then(fn {a, _} -> a end)
|> Enum.map(fn list -> list |> Enum.map(&String.to_integer/1) end)
|> Enum.map(fn list -> list |> Enum.sum() end)
|> Enum.sum()
|> then(&(&1 * String.to_integer(current_number)))
end
# Useless construct due to poor reading of the rules :(
def solve_all_boards_until_one_remains(boards, numbers) do
solve_all_boards_until_one_remains(boards, nil, numbers)
end
defp solve_all_boards_until_one_remains([last_board], _last_number, numbers) do
[current_number | rest_of_numbers] = numbers
IO.puts("Drawing: " <> current_number)
# IO.puts("Last board: " <> inspect last_board)
new_boards =
[last_board]
|> solve_all_boards_for_one_number(current_number)
if winning_board?(new_boards |> Enum.at(0)) do
{current_number, new_boards}
else
solve_all_boards_until_one_remains(new_boards, current_number, rest_of_numbers)
end
end
defp solve_all_boards_until_one_remains(boards, _last_number, numbers) do
[current_number | rest_of_numbers] = numbers
IO.puts("Drawing: " <> current_number)
IO.puts("Boards remaining: " <> inspect(length(boards)))
if length(boards) < 3 do
IO.puts("Boards: " <> inspect(boards))
end
new_boards =
boards
|> solve_all_boards_for_one_number(current_number)
|> Enum.reject(&winning_board?/1)
solve_all_boards_until_one_remains(new_boards, current_number, rest_of_numbers)
end
defp solve_all_boards_for_one_number(boards, number) do
boards
|> Enum.map(&solve_for_board(&1, number))
end
def solve_for_board(board, number) do
{cols, rows} = board
{
cols |> Enum.map(&solve_for_row(&1, number)),
rows |> Enum.map(&solve_for_row(&1, number))
}
end
def solve_for_row(combination, number) do
solve_for_row(combination, number, [])
end
defp solve_for_row([], _number, result), do: result
defp solve_for_row(combination, number, result) do
[head | tail] = combination
if head == number do
solve_for_row(tail, number, result)
else
solve_for_row(tail, number, [head | result])
end
end
end
[raw_numbers | boards] =
input
|> String.split("\n\n")
numbers =
raw_numbers
|> String.split(",", trim: true)
boards
|> Enum.map(&String.split(&1, "\n", trim: true))
|> Enum.map(&Day04a.clean_board/1)
|> Enum.map(&{&1, Day04a.pivot_board(&1)})
|> Day04b.solve_all_boards_until_one_remains(numbers)
|> Day04b.score_winner()
