From b3a6403639170f2231c8a0b21f581baadc1766e9 Mon Sep 17 00:00:00 2001
From: Dustin Swan <dustin@dustinswan.com>
Date: Sat, 4 Dec 2021 16:38:18 -0500
Subject: [PATCH] day 4. still feeling clumsy with racket

---
 .gitignore    |   1 +
 day4.rkt      | 103 +++++++++
 day4.test.txt |  19 ++
 day4.txt      | 601 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 724 insertions(+)
 create mode 100644 day4.rkt
 create mode 100644 day4.test.txt
 create mode 100644 day4.txt

diff --git a/.gitignore b/.gitignore
index e43b0f9..538c8c5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .DS_Store
+*~
diff --git a/day4.rkt b/day4.rkt
new file mode 100644
index 0000000..6d9f446
--- /dev/null
+++ b/day4.rkt
@@ -0,0 +1,103 @@
+#lang racket
+
+; util
+
+(define (split-on lst x) ; like splitOn in haskell. couldn't find this in the std lib..
+  (foldr (λ (element next)
+           (if (equal? element x)
+               (cons empty next)
+               (cons (cons element (first next)) (rest next))))
+         (list empty) lst))
+
+(define (map-map f lst) ; why tf can't i do (compose map map)
+  (map (λ (x) (map (λ (y) (f y)) x)) lst))
+
+(define (map-map-map f lst) ; (map . map . map)
+  (map (λ (x) (map-map f x)) lst))
+
+(define (transpose xss)
+  (apply map list xss))
+
+(define (all? f list)
+  (not (findf (λ (x) (not (f x))) list)))
+
+; IO and setup
+
+(define lines
+  (file->lines "day4.txt"))
+
+(define numbers ; grab first line of file, split into a list on ,
+  (map string->number (string-split (first lines) ",")))
+
+(define boards
+  (let* ([str-lists (split-on (drop lines 2) "")] ; split on empty lines
+         [split-up (map-map string-split str-lists)] ; convert '("1 2 3") to '("1" "2" "3")
+         [num-lists (map-map-map string->number split-up)]) ; convert '("1" "2" "3") to '(1 2 3)
+    (map-map-map (λ (x) (cons x #f)) num-lists))); change each cell to (<number>, <picked>)
+
+; part 1
+
+(define (mark-board board number) ; mark up a board with #t or #f based on the number
+  (map-map (λ (cell)
+             (match cell
+               [(cons num on) (cons num (or on (= num number)))]))
+           board))
+
+(define (mark-boards boards number) ; mark all boards based on the number
+  (map (λ (board) (mark-board board number)) boards))
+
+(define (all-winners? lst) ; check if all pairs in the list are #t
+  (all? (λ (x) (match x ([cons _ on] on))) lst))
+
+(define (is-winner? board) ; check if any row or column in the board is a winner
+  (let ([cols (transpose board)])
+    (or
+     (findf all-winners? board)
+     (findf all-winners? cols))))
+
+(define (mark-all-until-win boards numbers)
+  (foldl (λ (number acc)
+           (match acc
+             ([cons boards last-number]
+              (if (findf is-winner? boards) ; if we have any winners
+                  (cons boards last-number) ; just return the boards
+                  (cons (mark-boards boards number) number))))) ; otherwise keep marking
+         (cons boards 0) numbers))
+
+(define (sum-unmarked board)
+  (let* ([cells (apply append board)] ; flatten it
+         [unmarked (filter (λ (x) (not (cdr x))) cells)] ; filter out marked cells
+         [nums (map car unmarked)])
+         (foldl + 0 nums)))
+
+(define part1
+  (let* ([marked-up (mark-all-until-win boards numbers)] ; get (the final board state . last number)
+         [marked-boards (car marked-up)] ; car out the boards
+         [last-number (cdr marked-up)] ; cdr out the last number
+         [winning-board (findf is-winner? marked-boards)] ; find the winning board
+         [unmarked-sum (sum-unmarked winning-board)]) ; sum up the unmarked cells
+    (* unmarked-sum last-number)))
+
+part1
+
+; part 2
+
+(define (mark-all-until-one boards numbers)
+  (foldl (λ (number acc)
+           (match acc
+             ([cons boards last-number]
+              (if (= (length boards) 1) ; if we have only have 1 board left
+                  (cons boards last-number) ; just return it
+                  (let ([filtered-boards (filter (λ (x) (not (is-winner? x))) boards)]) ; otherwise filter out the winners
+                    (cons (mark-boards filtered-boards number) number)))))) ; and then keep marking
+         (cons boards 0) numbers))
+
+(define part2
+  (let* ([marked-up (mark-all-until-one boards numbers)] ; get (the final board state . last number)
+         [marked-boards (car marked-up)] ; car out the boards
+         [last-number (cdr marked-up)] ; cdr out the last number
+         [winning-board (findf is-winner? marked-boards)] ; find the winning board
+         [unmarked-sum (sum-unmarked winning-board)]) ; sum up the unmarked cells
+    (* unmarked-sum last-number)))
+
+part2
diff --git a/day4.test.txt b/day4.test.txt
new file mode 100644
index 0000000..669a51d
--- /dev/null
+++ b/day4.test.txt
@@ -0,0 +1,19 @@
+7,4,9,5,11,17,23,2,0,14,21,24,10,16,13,6,15,25,12,22,18,20,8,19,3,26,1
+
+22 13 17 11  0
+ 8  2 23  4 24
+21  9 14 16  7
+ 6 10  3 18  5
+ 1 12 20 15 19
+
+ 3 15  0  2 22
+ 9 18 13 17  5
+19  8  7 25 23
+20 11 10 24  4
+14 21 16 12  6
+
+14 21 17 24  4
+10 16 15  9 19
+18  8 23 26 20
+22 11 13  6  5
+ 2  0 12  3  7
diff --git a/day4.txt b/day4.txt
new file mode 100644
index 0000000..6095521
--- /dev/null
+++ b/day4.txt
@@ -0,0 +1,601 @@
+83,69,34,46,30,23,19,75,22,37,89,78,32,39,11,44,95,43,26,48,84,53,94,88,18,40,62,35,27,42,15,2,91,20,4,64,99,71,54,97,52,36,28,7,74,45,70,86,98,1,61,50,68,6,77,8,57,47,51,72,65,3,49,24,79,13,17,92,41,80,63,67,82,90,55,0,10,93,38,21,59,73,33,31,9,76,5,66,16,58,85,87,12,29,25,14,96,56,60,81
+
+68 73 98 51 49
+82 56 87 64  8
+46  7 21 38 30
+66  5 86 97 74
+60 63 76 55 39
+
+92 20 87 77 52
+72 29 81 24 64
+26 16 19 79 68
+ 8 53 90 14 74
+28 89 78 54 15
+
+13 17 35  2 85
+37 87 57 74 65
+60 21 18 98 96
+ 4 51 46 84  0
+90 75 80 41 64
+
+83 98  4 78 45
+90 62 71 68 39
+47 81 96 73 43
+ 9 94 65 99 60
+44  5 29 50  6
+
+23 43 42 35  9
+82 90 49 70 59
+58 38 44 55 85
+ 3 99 88 65 61
+71 53 17 37  4
+
+58 38 47 84 89
+60 87 80 92 75
+57 83 40 62 25
+11  7 33 76 70
+82 31 53 56 90
+
+96 40 50 21 38
+58 77 64 98 86
+ 9 68 78 55 10
+51 74 71 28 16
+49 45 32  7 57
+
+71 98 26  5 95
+21 53 48 35 92
+ 4 90  9 45 82
+67 28 33 34 58
+85 41 80 64 19
+
+98 36 33 34 55
+15 81 97 56 96
+91 73 32 63 83
+31  3 85 80 38
+71 93 87 86 27
+
+19 15 97 31 26
+56 58 54 87  1
+ 9 28 23  7 20
+38 67 52 73 88
+95 77 27 91 81
+
+81 64 19 67 10
+97 73 46 31  3
+93 77  8  7 57
+ 0 28 87 42 66
+17 79 58 14 18
+
+43 17 63  7 49
+28 27 31 23 41
+65 34 51 70 77
+73 56 74 96 72
+94 86 48 71 40
+
+97 43 56  0 30
+60 71 34  1 96
+10 72 28 82 84
+36 22  9 20 67
+ 8 29 92  5 41
+
+28 49  8 78 53
+41 32  3  4 88
+56 68 18 65 54
+24  5 71 21 75
+52 15 47 83 79
+
+26 47  2 22  9
+ 6 81 53 17 88
+58 25 55 31 19
+42 27 85 97 14
+64 52 66 63 51
+
+80 43 88 42 51
+17 18 84 60 24
+34 48 89 33 10
+ 7 21 83  0 26
+28 86 25 58 16
+
+71 77  2 99 16
+90 59 54 27 10
+78 51 26 12 80
+25 58 53 33 83
+31  7 96 38 95
+
+87 91  7 76  5
+96  1 16 62 35
+22 61 29 27 12
+57 50 78  4 65
+ 3 97 73 82 94
+
+93 63 43 22 71
+12 74 41 64 62
+81  2 37 99 27
+26 39 66 30 20
+77 78 18 53  5
+
+72 61 21 59 41
+18 49 95 51 30
+63 75 10 47 27
+83 11  8 39 68
+ 9 99 67 44 77
+
+29 98 74 11 17
+44 80  1 78  6
+73 20 32  0 27
+76 37 77 41 24
+36 97 87 89 68
+
+12 35 84 98 87
+33 78 64 85  3
+18 14 71 54 93
+63 34 61 57 22
+36 20 91 69 55
+
+84 74 25 67 38
+59 60 56 68 81
+41 51 23 98 92
+30 35 45 17 83
+71 97 21  5 94
+
+95 10 92 27 34
+15 67 76 14 98
+85 81 40 38 58
+ 8 17  6 59 48
+78 73 84 11 46
+
+25 50 40 69 27
+89 59 17 86 20
+ 3 98 76 90  9
+41 75 21 29 55
+47 94 23  6 68
+
+82 90 99 65 52
+81 18 87 42  6
+56 79 36 96 60
+70 20 39 22 14
+71 88 86 46 48
+
+99 37 16 39 46
+82 27 12 19 47
+25 80 38 22 55
+76  1  7 54 28
+60 97 56 32 17
+
+79  5 56 14 51
+86 57 18 89 81
+97 88 54 60 34
+50 25 62 66 98
+23 65 87 63 11
+
+71 10  5 63 73
+14 70  7 36 20
+38 75 59 33 17
+18  3 72 46 76
+98 80 64 48 30
+
+54 21 56 86 61
+71 45 16  5 66
+ 0 12 94 70  1
+37 98 26 93 18
+87 90 24 44 91
+
+18 10 72 81 48
+67 80 42 25 33
+92 34  0 27 26
+77 99 57  9 46
+82 15 54 21 52
+
+73 18 80 27 50
+58 97 84 81 21
+94 68  8 57  9
+56 98 67 36 92
+86 53 35 41 89
+
+86 65  2 74  5
+ 3 80 19 41 48
+98 99 24 50 57
+ 8 59 53 67 91
+62 83 72  9 14
+
+56 69  7 38 87
+39 71 84 41 88
+23 94  1 97 33
+73 14  2 79 72
+26 91 45  9  6
+
+17 40 97 51 57
+92 25 38 26 23
+32 44 83 87 49
+54 74 33  7 12
+14 36 30  8 98
+
+56 26  3 73 32
+90 80 23  0 27
+59 19 33 78 52
+21  1 20 86 34
+85 48 37 97 67
+
+23 13 90 35 44
+30 96 18 14 92
+80  5 97 11 58
+12 50 33 65 78
+48 26 86 15  7
+
+70 32 62 92 13
+23  1 21 50 59
+79 26 11 65 76
+90 54 64 63 31
+ 0 19 86 33  9
+
+69 60  3 94 20
+35 72 82 42 45
+66  6 52 64 62
+19 28 83  1 98
+76 74 12  9 54
+
+32 29 46 57 50
+80 10 42 24 82
+56 41 90  7 12
+89 78 53 95  9
+26 52 67 27 83
+
+85 83  2 65 71
+35 66 55 87 39
+90 56 97 81  9
+73 32 98 84 95
+88 33 34 25 86
+
+78  8 34 21 23
+ 2 86 10  4 58
+31 62 35 91 63
+81 90 69 15 47
+41 12 61 72 36
+
+10 95 68 87 25
+59 45 54 92 82
+34 81 12 61 83
+89 69 98 72 44
+84 20 51 36  1
+
+59 94 26 76 54
+39 21 86 13 48
+58 61 75 80 62
+ 8 88 74 24 19
+42 38 72 60 93
+
+82 46 54 48 20
+53 94 57 98 83
+15 10 39 17 91
+89 47  4 35 27
+61 42 92 13  8
+
+97 73  9 67 58
+87 49 96 88 94
+68 38 11 41 43
+26 51  4 22  0
+18  2 84 62 33
+
+79 25 51 78 93
+76 49 69 87 26
+63 71 67 28 34
+48 38 99 66 11
+44 61 75 96 23
+
+66 79 37 23 98
+43 94 49 27 36
+21 86 34 24 42
+ 4  8 85 63 32
+74 82 68 92 72
+
+12 77 87 53 76
+71 66 10 68 36
+74 49 27 16 34
+98 21 54 93 18
+95 61 97 65 32
+
+60 91 68 11 76
+66 62 65  3 41
+ 6 84 61 58 73
+ 7 28 63 75 55
+35 45 98 47 81
+
+85 75 46 45 58
+95 92 73 99 47
+25 97 76 15 23
+19  5 37 36 65
+96  8 24 49 61
+
+53 60 16 94 59
+10 47 82 17 89
+86 91  1 40 45
+34 76 38 97 63
+25 85 57 27 93
+
+77 95 20 24 93
+37  4 23 39 35
+81  2 56 18 87
+46 75 52 51 50
+88  8 83 80 27
+
+20 47 27 52  2
+97  0 17 64 11
+53  9 69 88 77
+13 89 28 21 36
+71 33 31  6 68
+
+45 25  6 18  7
+51 84 82 83 81
+13 65 34 93 71
+87 92 49  8 24
+76 29 53 96 58
+
+15 41 65 85 29
+78 30 93 98 67
+36 58 12  1 25
+ 3 10 88  9 96
+ 8 53  7 14  6
+
+78 37 50 99 51
+42 19 40 62 54
+89 38 64 70 56
+96 72 41 43 95
+90 91 17 28 59
+
+23  5 45 80 93
+14 75 78 25 86
+21 24 73 30 34
+39 74 22 19 49
+72 31  1 77 57
+
+59  8 57 68 32
+71 19  9 29 63
+ 3 92 40 79 31
+87 75 99 88  2
+15 20 85 89 44
+
+ 7 41 16 15 46
+76  5 51 11 38
+28 70 68 91 66
+56 94 59 34 86
+72 80 42 75 65
+
+92 95 48 65 89
+27 64 69 15 33
+93 47 30  7 63
+91 35 29 42 72
+90 23 11 50 54
+
+97 17 66 92 91
+81 23 12  6 93
+48 25 27 16 54
+21 32 50 94 98
+15 55 40 11 84
+
+66 56 95 44 33
+26 11 41 22 86
+ 2  1 50 79 32
+70 74 84  5 90
+92  0  6 73 40
+
+34 48 28 98 88
+66 60 46 54 91
+43 21 81 95 33
+53 87 82 79 92
+45 62 58 99 96
+
+ 6 16 70 86  9
+19 95 37 96 62
+ 3 42 24 60 15
+55 56 92 80 26
+72 85 91 73 94
+
+72 73 94 15  4
+ 3 40 67 21 84
+45 33 60 82 10
+48  6 29 79 70
+27 66 13 38 47
+
+31  0 56 89 61
+62 49 37 73  1
+63 68 38 83 44
+70 17 69 14 81
+72 58 52 50 79
+
+46 18 61 11 14
+51 58 94 98 69
+ 2  0 93  6 95
+92 17  3 37 33
+48 20 45 16 13
+
+98 74 36 23  6
+65 17 78 95 96
+68 63 47 16 18
+87 30 53 51 57
+69 11 44 75 89
+
+25 56  5 53  3
+58  1 91  2 47
+72 75 44 96 70
+30 63 10 93 74
+67 55 82 32 61
+
+31 97 28 14 48
+87 50 95 23 83
+33 34  4 46 94
+43 84 86 13 40
+52 64 16 88 81
+
+40 30 14 36 90
+ 2 25 12 10 33
+18 27 78 73 60
+11 92 52 69 93
+19 22 35 17 61
+
+42 45 49  8 14
+21 18 69 12 27
+25 76 63 28 64
+52  7 77 58 39
+87 89 88 38  4
+
+40 57 53 48 46
+13 59 23 55 61
+ 1 50 83 73 31
+18 47 29 65 27
+76 49 33 51 26
+
+65 76 78 90 30
+25 83  4 23  3
+53 34 20 36 37
+18 66 12 45 59
+68 50 74 96 48
+
+39 51 92  7 22
+11 47 44 26 55
+73 52 38 45 59
+72 76 17 56 97
+83 13 70 29 37
+
+25 12 84 51 14
+ 2 22 85 13 10
+73 93 67 72 80
+56 90 60 42 61
+36 16 50 70 97
+
+ 1 60 44 32 47
+71 76 69 27 54
+22 43 12 72  9
+17 90 53 19 95
+41 65 62 11 63
+
+76 64 33  3 81
+28 20 95 98 79
+58 23 87 69 29
+31 72 55 49 36
+15 67 83 37 52
+
+52 87 40 67 91
+19  7 80 88 29
+97 28 50 63 53
+43 89 35 69 75
+79 65 58 78 86
+
+21 52 43 71 69
+26 47 81 91 20
+70 90  6 49 78
+11 72 82 83  2
+62 64 66 93 48
+
+47 78 38 10 82
+12 32 71 41 46
+18 13 74 63 90
+86 96 17 97  9
+70  4 59 52  6
+
+29 49 54 76  5
+42 99 92 52 26
+48 80 65  9 89
+87 68 47 24 78
+74  2 85 43 56
+
+21  7 44 36  3
+ 0 72 66 28 74
+99 68 83 53 30
+96 81  4 69 23
+15 20 31 41 42
+
+87 78 21  6 62
+68 95 30  5 20
+81 54 42 50 70
+18 39 93 35 72
+22 97 73 74 75
+
+25 24 62  5 54
+85 31 88 40 76
+48 44 15  3  4
+61 47 56 72  9
+11 49 50 78 39
+
+54 30 52 70 16
+63 49 91  3 51
+71 36 46 79 67
+80 66 31 57 43
+45  9 84 17 35
+
+68 41 32 23 24
+95 62 87 97  5
+16  2 48 17  1
+59  9 35 96 22
+50 70 44 89 31
+
+21 35 47 36  2
+33 49 77 39 60
+70 91 97 18 66
+25 95 22 87 20
+69 27 76 52 11
+
+42 40 26 61 98
+33 88 79 72 73
+ 7 57 71  0 82
+ 2 21 74 63 41
+58 96 50 13  4
+
+80 84 96 31 38
+58 75 19 91  6
+10 54 52 66 81
+55 35 47 23 69
+95 40 21 17 79
+
+58 68 27  0 81
+49 51 93 83 23
+ 5 90  8 76 57
+53 33 45 75 84
+72 28 38 43 40
+
+73 62 93 77 17
+ 4 89 82 85 18
+33 57 58 55 49
+48 11 94 14 72
+ 7 53 34 69 21
+
+19 37 69 48 13
+ 5 14 46  2 86
+40 87 95 79 36
+81 62 70 23 82
+51 43 91 29  9
+
+70 16  3  5 38
+62 85 19 15 41
+36 42 13 31 87
+58 66 27 49  6
+82 54 91 23 10
+
+67 63 60 80 66
+16 30  2 85 97
+45 52 62 21 49
+83 75 76 10 82
+47 90 72  5  9
+
+ 3 11 31 61 99
+42 62 15 64 40
+30 95  7 81 28
+63 50 74 77 34
+38 89 73  2 92
+
+34 73 60 32 56
+49 35 44 79 83
+64 61 57  5 24
+72 58  8 66 77
+94 31 55 67 74
+
+49 17 22 97 88
+ 0 16 14 93 31
+28 73  6 82 90
+80 45 92 55 78
+ 3 42 65 37 29
+
+23 61 97  1 69
+53 98 28 52 19
+66 51 46 77 15
+34 36 47 80 14
+ 7 89 62  9 49