From 9cdb24bfa546129db12d26c6a364ca2dd8560b13 Mon Sep 17 00:00:00 2001
From: Jonathan Chan <jonathanhwchan@gmail.com>
Date: Sat, 4 Dec 2021 21:32:06 -0800
Subject: [PATCH] Day 05.

---
 input/05.txt | 500 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lib.rkt      |   4 +-
 src/05.rkt   |  47 +++++
 3 files changed, 549 insertions(+), 2 deletions(-)
 create mode 100644 input/05.txt
 create mode 100644 src/05.rkt

diff --git a/input/05.txt b/input/05.txt
new file mode 100644
index 0000000..2ce7301
--- /dev/null
+++ b/input/05.txt
@@ -0,0 +1,500 @@
+629,581 -> 123,75
+921,643 -> 452,643
+498,588 -> 503,593
+861,137 -> 102,896
+603,339 -> 603,137
+138,738 -> 117,738
+14,60 -> 41,60
+606,810 -> 157,361
+980,21 -> 56,945
+43,731 -> 910,731
+745,329 -> 962,329
+800,916 -> 390,916
+737,96 -> 737,24
+978,777 -> 978,592
+232,638 -> 232,611
+833,888 -> 454,509
+627,659 -> 763,523
+871,300 -> 310,861
+987,224 -> 987,909
+54,234 -> 852,234
+413,111 -> 277,111
+264,600 -> 840,24
+180,477 -> 780,477
+837,197 -> 837,796
+943,438 -> 769,438
+260,801 -> 318,801
+645,717 -> 593,717
+542,677 -> 115,250
+255,251 -> 726,722
+57,219 -> 57,147
+898,683 -> 466,251
+925,900 -> 697,900
+264,384 -> 12,384
+240,584 -> 816,584
+962,932 -> 151,121
+524,163 -> 253,434
+981,557 -> 981,942
+934,176 -> 454,656
+872,439 -> 111,439
+449,57 -> 161,57
+50,72 -> 50,54
+104,141 -> 603,141
+219,886 -> 747,358
+774,257 -> 110,921
+82,142 -> 845,905
+416,859 -> 129,572
+326,640 -> 181,785
+192,818 -> 192,408
+309,876 -> 309,811
+536,860 -> 536,740
+789,472 -> 789,625
+760,135 -> 647,22
+425,788 -> 329,884
+13,11 -> 971,969
+342,772 -> 456,772
+85,758 -> 500,343
+322,167 -> 830,675
+977,117 -> 107,117
+148,902 -> 134,902
+812,940 -> 45,173
+544,218 -> 88,674
+110,536 -> 110,927
+989,127 -> 129,987
+89,96 -> 671,678
+604,368 -> 604,127
+89,551 -> 89,460
+590,749 -> 590,147
+390,224 -> 899,224
+25,765 -> 488,302
+624,265 -> 339,265
+127,712 -> 127,797
+133,53 -> 133,168
+934,978 -> 638,978
+443,119 -> 672,119
+691,796 -> 486,591
+153,64 -> 153,859
+588,78 -> 381,78
+205,655 -> 90,655
+965,625 -> 965,388
+699,500 -> 699,227
+35,246 -> 791,246
+305,372 -> 305,326
+954,695 -> 416,695
+192,582 -> 712,62
+759,87 -> 346,500
+73,153 -> 903,983
+386,12 -> 937,12
+287,256 -> 19,524
+725,761 -> 391,427
+159,128 -> 159,985
+839,853 -> 55,69
+818,257 -> 974,257
+754,645 -> 738,645
+164,950 -> 904,210
+208,370 -> 381,370
+467,876 -> 42,876
+779,708 -> 779,56
+152,504 -> 465,817
+808,721 -> 965,564
+957,131 -> 649,131
+984,12 -> 23,973
+283,915 -> 283,347
+775,13 -> 340,448
+588,294 -> 588,360
+775,976 -> 775,497
+891,292 -> 551,292
+43,860 -> 849,860
+639,384 -> 639,942
+932,967 -> 932,762
+109,66 -> 828,785
+107,369 -> 107,480
+606,445 -> 766,605
+429,10 -> 588,10
+895,832 -> 586,523
+938,633 -> 938,152
+907,683 -> 242,683
+748,384 -> 748,771
+256,276 -> 954,276
+975,444 -> 975,33
+404,469 -> 84,469
+105,688 -> 55,688
+73,105 -> 695,105
+402,335 -> 402,567
+524,797 -> 524,603
+188,171 -> 61,44
+954,30 -> 11,973
+794,400 -> 510,116
+592,845 -> 375,845
+457,679 -> 634,679
+35,635 -> 641,635
+652,667 -> 541,556
+393,128 -> 393,884
+302,254 -> 302,297
+302,145 -> 279,168
+64,274 -> 432,274
+560,154 -> 560,511
+928,755 -> 928,722
+578,430 -> 891,430
+505,463 -> 505,476
+62,248 -> 661,248
+573,603 -> 573,781
+61,800 -> 61,723
+925,357 -> 925,233
+883,336 -> 753,466
+535,647 -> 48,160
+981,931 -> 269,219
+980,981 -> 14,15
+404,675 -> 112,383
+861,472 -> 568,765
+17,439 -> 17,530
+839,411 -> 754,411
+944,408 -> 793,257
+910,963 -> 910,382
+640,101 -> 987,101
+33,100 -> 779,846
+799,981 -> 799,985
+787,610 -> 787,990
+967,567 -> 502,567
+369,452 -> 876,959
+830,725 -> 604,499
+112,255 -> 726,869
+746,291 -> 930,475
+170,795 -> 170,72
+587,183 -> 981,183
+588,226 -> 588,328
+643,747 -> 504,747
+882,445 -> 627,445
+849,274 -> 849,135
+536,225 -> 212,225
+143,538 -> 143,832
+319,25 -> 984,690
+278,189 -> 278,526
+527,414 -> 527,704
+935,141 -> 122,954
+623,626 -> 111,114
+211,495 -> 211,924
+146,914 -> 836,224
+573,423 -> 956,423
+902,188 -> 463,188
+807,950 -> 925,950
+956,60 -> 35,981
+791,480 -> 383,888
+886,872 -> 886,471
+441,840 -> 65,464
+367,596 -> 367,846
+566,799 -> 574,799
+590,202 -> 803,202
+988,17 -> 17,988
+566,640 -> 63,137
+304,316 -> 304,470
+452,808 -> 452,455
+982,647 -> 494,159
+654,102 -> 654,580
+760,122 -> 610,272
+349,859 -> 114,624
+72,520 -> 72,790
+272,910 -> 272,848
+751,311 -> 751,911
+396,771 -> 396,356
+37,909 -> 904,42
+903,636 -> 939,636
+661,911 -> 661,967
+246,367 -> 246,451
+179,659 -> 455,935
+65,977 -> 975,67
+525,539 -> 525,523
+211,310 -> 850,310
+327,158 -> 961,158
+224,46 -> 15,255
+177,624 -> 177,297
+949,833 -> 949,711
+732,43 -> 616,159
+537,397 -> 112,822
+432,490 -> 509,567
+70,130 -> 872,932
+810,584 -> 810,679
+863,967 -> 145,249
+919,840 -> 574,840
+955,534 -> 955,77
+90,685 -> 90,858
+24,974 -> 986,12
+980,940 -> 115,75
+41,154 -> 705,818
+196,976 -> 901,271
+80,855 -> 526,409
+190,314 -> 818,942
+195,400 -> 195,968
+698,976 -> 698,171
+351,753 -> 292,753
+433,163 -> 433,411
+37,615 -> 62,615
+696,724 -> 696,170
+625,793 -> 625,359
+387,469 -> 387,552
+24,568 -> 522,70
+569,695 -> 272,695
+16,87 -> 634,705
+986,611 -> 986,827
+581,196 -> 581,180
+373,716 -> 373,304
+562,767 -> 562,493
+506,430 -> 474,430
+362,878 -> 624,616
+888,288 -> 33,288
+483,480 -> 709,706
+261,879 -> 896,879
+196,71 -> 196,462
+717,414 -> 296,414
+973,591 -> 973,149
+390,140 -> 390,727
+966,932 -> 913,932
+693,824 -> 902,824
+724,898 -> 724,46
+557,802 -> 902,802
+968,398 -> 968,124
+784,727 -> 498,441
+938,618 -> 938,863
+119,114 -> 119,636
+110,933 -> 374,933
+406,760 -> 895,271
+499,526 -> 834,526
+844,464 -> 844,535
+32,899 -> 903,28
+796,423 -> 796,498
+188,144 -> 965,144
+135,828 -> 591,372
+616,558 -> 616,129
+356,818 -> 356,540
+406,894 -> 519,894
+303,31 -> 821,549
+82,472 -> 708,472
+64,314 -> 355,314
+236,341 -> 489,341
+839,118 -> 544,118
+680,804 -> 96,220
+204,105 -> 906,807
+357,662 -> 685,334
+463,797 -> 555,797
+973,913 -> 276,216
+614,852 -> 25,263
+958,275 -> 812,421
+963,15 -> 26,952
+743,136 -> 328,136
+975,937 -> 625,937
+984,34 -> 38,980
+19,516 -> 432,103
+802,827 -> 802,78
+12,971 -> 945,38
+335,331 -> 290,331
+890,803 -> 170,803
+950,52 -> 950,417
+68,391 -> 524,847
+862,699 -> 786,699
+542,323 -> 578,323
+454,171 -> 970,687
+980,24 -> 990,24
+253,56 -> 600,403
+571,27 -> 622,27
+966,400 -> 527,400
+624,914 -> 624,43
+85,819 -> 764,140
+204,76 -> 958,830
+208,77 -> 208,284
+668,342 -> 668,373
+633,468 -> 786,621
+972,704 -> 980,704
+552,601 -> 552,953
+912,28 -> 199,741
+884,403 -> 491,10
+731,897 -> 115,281
+492,33 -> 492,296
+295,130 -> 691,130
+741,389 -> 403,51
+974,64 -> 68,970
+954,518 -> 629,518
+392,722 -> 242,872
+523,762 -> 183,422
+431,664 -> 782,313
+750,696 -> 665,696
+426,243 -> 308,243
+602,857 -> 602,598
+849,682 -> 599,682
+723,514 -> 447,514
+403,898 -> 598,898
+139,555 -> 124,555
+570,151 -> 135,151
+205,99 -> 119,185
+291,271 -> 647,627
+537,541 -> 871,207
+647,596 -> 630,596
+870,967 -> 51,148
+470,205 -> 470,692
+238,914 -> 238,55
+285,661 -> 578,661
+878,343 -> 140,343
+274,175 -> 274,944
+193,829 -> 193,332
+169,255 -> 824,910
+695,389 -> 472,389
+707,336 -> 543,336
+860,983 -> 567,690
+732,595 -> 42,595
+723,603 -> 161,603
+206,937 -> 328,937
+981,26 -> 62,26
+624,696 -> 624,756
+317,626 -> 317,717
+353,475 -> 353,809
+759,54 -> 303,54
+96,493 -> 70,493
+457,675 -> 457,812
+955,577 -> 955,673
+10,606 -> 559,606
+945,872 -> 555,872
+818,651 -> 818,51
+869,314 -> 90,314
+271,490 -> 458,490
+48,880 -> 48,495
+310,62 -> 310,694
+61,988 -> 985,64
+558,128 -> 745,315
+594,695 -> 549,695
+98,114 -> 98,204
+107,513 -> 577,983
+721,859 -> 150,288
+102,101 -> 903,902
+971,547 -> 501,547
+857,127 -> 290,694
+486,117 -> 230,117
+550,46 -> 968,464
+946,965 -> 40,59
+757,565 -> 757,613
+99,597 -> 99,763
+352,287 -> 352,22
+826,781 -> 942,781
+631,667 -> 631,869
+438,778 -> 736,480
+974,988 -> 12,26
+730,69 -> 417,382
+879,987 -> 10,118
+433,256 -> 142,256
+254,285 -> 941,972
+828,351 -> 257,922
+830,751 -> 830,347
+789,244 -> 355,244
+607,451 -> 607,838
+853,198 -> 265,198
+65,738 -> 65,921
+122,676 -> 122,801
+493,252 -> 639,252
+42,977 -> 937,82
+544,296 -> 271,23
+772,436 -> 772,979
+259,403 -> 259,757
+436,193 -> 436,478
+227,395 -> 216,395
+672,205 -> 711,244
+116,307 -> 116,337
+768,332 -> 768,314
+380,867 -> 380,746
+57,357 -> 57,247
+326,502 -> 640,188
+151,512 -> 308,512
+481,226 -> 481,935
+835,205 -> 868,238
+535,920 -> 535,158
+314,106 -> 221,13
+304,189 -> 357,189
+349,169 -> 349,150
+568,765 -> 849,484
+680,877 -> 392,589
+170,924 -> 984,924
+52,935 -> 714,273
+542,667 -> 708,667
+583,522 -> 263,842
+710,50 -> 710,500
+713,272 -> 713,897
+70,843 -> 70,747
+319,874 -> 290,874
+56,148 -> 115,89
+77,136 -> 928,987
+867,956 -> 152,241
+206,171 -> 688,171
+834,81 -> 834,726
+186,482 -> 888,482
+785,467 -> 537,467
+232,100 -> 338,206
+556,921 -> 556,469
+630,16 -> 976,16
+168,977 -> 168,383
+784,819 -> 694,819
+298,116 -> 47,116
+577,19 -> 577,729
+767,236 -> 682,236
+222,277 -> 222,952
+119,196 -> 18,95
+26,500 -> 26,714
+324,605 -> 223,706
+296,224 -> 582,224
+425,582 -> 425,371
+922,365 -> 674,365
+377,302 -> 841,766
+342,99 -> 342,469
+181,470 -> 181,473
+201,803 -> 201,335
+593,252 -> 262,583
+138,14 -> 138,375
+148,713 -> 148,733
+208,710 -> 777,710
+333,782 -> 20,782
+258,680 -> 258,368
+978,195 -> 301,195
+600,350 -> 600,22
+83,442 -> 301,442
+747,173 -> 67,173
+869,884 -> 869,291
+832,979 -> 832,349
+457,476 -> 457,472
+521,372 -> 521,630
+440,408 -> 830,408
+530,175 -> 530,600
+664,158 -> 282,158
+942,757 -> 942,852
+76,763 -> 76,658
+379,831 -> 379,75
+74,35 -> 391,35
+39,349 -> 794,349
+591,211 -> 226,211
+143,215 -> 143,808
+965,19 -> 26,958
+475,33 -> 623,181
+791,212 -> 791,913
+95,942 -> 927,110
+977,434 -> 755,656
+340,762 -> 404,698
+518,321 -> 61,778
+238,620 -> 238,666
+568,522 -> 568,757
+716,821 -> 716,404
+57,34 -> 929,906
+949,483 -> 785,483
+408,255 -> 408,191
+590,62 -> 436,62
+729,44 -> 591,182
+557,740 -> 902,395
+900,467 -> 741,467
+90,258 -> 653,258
+653,323 -> 420,556
+85,933 -> 592,933
+938,59 -> 218,779
+226,467 -> 226,937
+587,330 -> 587,51
+487,797 -> 924,797
+216,11 -> 216,875
+316,263 -> 301,263
+981,487 -> 981,519
+97,936 -> 896,137
+704,560 -> 548,560
+44,340 -> 617,340
+160,751 -> 787,124
diff --git a/lib.rkt b/lib.rkt
index a083189..c7f1889 100644
--- a/lib.rkt
+++ b/lib.rkt
@@ -122,8 +122,8 @@
 ;; sum : (listof number) -> number
 (define (sum ns) (apply + ns))
 
-;; != : number -> number -> boolean
-(define (!= n1 n2)
+;; ≠ : number -> number -> boolean
+(define (≠ n1 n2)
   (not (= n1 n2)))
 
 ;; nzero? : number -> boolean
diff --git a/src/05.rkt b/src/05.rkt
new file mode 100644
index 0000000..750dde5
--- /dev/null
+++ b/src/05.rkt
@@ -0,0 +1,47 @@
+#lang curly-fn racket
+
+(require "../lib.rkt")
+
+(define input (problem-input 5))
+
+(define lines
+  (for/list ([line input])
+    (~> line
+        (regexp-match #px"(\\d+),(\\d+) -> (\\d+),(\\d+)" _)
+        rest
+        (map string->number _))))
+
+(define-values (hvs diags)
+  (partition #{or (= (first %) (third %))
+                  (= (second %) (fourth %))} lines))
+
+(define (count-crosses grid)
+  (count #{> % 1} (hash-values grid)))
+
+(define grid (make-hash))
+
+(for ([hv hvs])
+  (match hv
+    [`(,x ,y1 ,x ,y2)
+     (for ([y (range (min y1 y2) (add1 (max y1 y2)))])
+       (hash-update! grid (list x y) add1 0))]
+    [`(,x1 ,y ,x2 ,y)
+     (for ([x (range (min x1 x2) (add1 (max x1 x2)))])
+       (hash-update! grid (list x y) add1 0))]))
+
+(define part1 (count-crosses grid))
+
+(for ([diag diags])
+  (match diag
+    [`(,x1 ,y1 ,x2 ,y2)
+     (define-values (x-offset x-step)
+       (if (>= x2 x1) (values add1 1) (values sub1 -1)))
+     (define-values (y-offset y-step)
+       (if (>= y2 y1) (values add1 1) (values sub1 -1)))
+     (for ([x (range x1 (x-offset x2) x-step)]
+           [y (range y1 (y-offset y2) y-step)])
+       (hash-update! grid (list x y) add1 0))]))
+
+(define part2 (count-crosses grid))
+
+(show-solution part1 part2)
\ No newline at end of file