diff --git a/day5.rkt b/day5.rkt new file mode 100644 index 0000000..83735da --- /dev/null +++ b/day5.rkt @@ -0,0 +1,59 @@ +#lang racket + +(define (map-map f lst) ; map . map + (map (λ (x) (map (λ (y) (f y)) x)) lst)) + +(define/match (add-dx-dy points) + [((list (list x1 y1) (list x2 y2))) + (let* ([dx (- x2 x1)] + [dy (- y2 y1)] + [len (max (abs dx) (abs dy))]) + (list (list x1 y1) (list x2 y2) dx dy len))]) + +(define (vectorize line) + (let* ([parts (string-split line " -> ")] ; '("0,9 -> 5,9") -> '("0,9" "5,9") + [strings (map (λ (part) (string-split part ",")) parts)] ; '("0,9" "5,9") -> '(("0" "9") ("5" "9")) + [nums (map-map string->number strings)] ; '(("0" "9") ("5" "9")) -> '((0 9) (5 9)) + [vectors (add-dx-dy nums)]) ; '((x1 y2) (x2 y2) dx dy length) + vectors)) + +(define/match (non-diagonal? vect) + [((list _ _ dx dy _)) (or (= dx 0) (= dy 0))]) + +(define/match (get-points-from-vect vect) ; takes vect '((x1 y1) (x2 y2) dx dy len) and returns a list of points it hits '((x1 y1) (x2 y2) ..) + [((list (list x1 y1) (list x2 y2) dx dy len)) + (let loop ([i len]) + (if (= i 0) ; at the end + (list (list x1 y1)) ; return this point + (append (list (list (+ x1 (/ (* dx i) len)) (+ y1 (/ (* dy i) len)))) ; return the next point.. + (loop (sub1 i)))))]) ; appended to the result of recursing with i - 1 + +(define (add-point ht point) + (let ([dups (hash-ref ht point 0)]) + (hash-set! ht point (+ 1 dups)))) + +(define (travel-and-add ht vects) + (for ([i (in-list vects)]) + (let ([points (get-points-from-vect i)]) + (map (λ (p) (add-point ht p)) points)))) + +(define part1 + (let* ([lines (file->lines "day5.txt")] + [vectors (map vectorize lines)] + [non-diagonals (filter non-diagonal? vectors)] + [ht (make-hash)] + [points-hit (travel-and-add ht non-diagonals)] + [counts (hash-values ht)]) + (length (filter (λ (x) (> x 1)) counts)))) + +part1 + +(define part2 + (let* ([lines (file->lines "day5.txt")] + [vectors (map vectorize lines)] + [ht (make-hash)] + [points-hit (travel-and-add ht vectors)] + [counts (hash-values ht)]) + (length (filter (λ (x) (> x 1)) counts)))) + +part2 \ No newline at end of file diff --git a/day5.test.txt b/day5.test.txt new file mode 100644 index 0000000..b258f68 --- /dev/null +++ b/day5.test.txt @@ -0,0 +1,10 @@ +0,9 -> 5,9 +8,0 -> 0,8 +9,4 -> 3,4 +2,2 -> 2,1 +7,0 -> 7,4 +6,4 -> 2,0 +0,9 -> 2,9 +3,4 -> 1,4 +0,0 -> 8,8 +5,5 -> 8,2 diff --git a/day5.txt b/day5.txt new file mode 100644 index 0000000..4efb168 --- /dev/null +++ b/day5.txt @@ -0,0 +1,500 @@ +348,742 -> 620,742 +494,864 -> 494,484 +193,136 -> 301,136 +342,692 -> 342,538 +234,525 -> 102,393 +72,964 -> 847,189 +639,430 -> 99,970 +398,791 -> 398,187 +181,144 -> 205,168 +607,617 -> 416,617 +98,339 -> 98,437 +763,119 -> 176,119 +450,848 -> 450,664 +293,133 -> 293,98 +308,98 -> 308,15 +157,21 -> 405,269 +792,471 -> 409,471 +42,955 -> 956,41 +895,269 -> 895,884 +629,635 -> 392,635 +169,23 -> 273,127 +250,847 -> 250,665 +709,56 -> 709,626 +938,599 -> 669,868 +913,46 -> 458,501 +844,417 -> 844,424 +178,651 -> 640,189 +226,266 -> 149,266 +654,421 -> 654,499 +368,780 -> 368,38 +183,743 -> 497,429 +942,34 -> 387,589 +987,461 -> 987,348 +485,275 -> 330,275 +33,460 -> 456,883 +606,304 -> 606,628 +755,170 -> 755,187 +342,862 -> 250,954 +866,125 -> 151,840 +795,489 -> 599,685 +905,525 -> 905,457 +99,620 -> 99,339 +899,507 -> 699,707 +627,444 -> 923,444 +798,80 -> 419,459 +580,237 -> 580,907 +947,336 -> 947,727 +491,466 -> 546,411 +335,221 -> 458,221 +547,70 -> 407,210 +520,80 -> 647,80 +835,58 -> 835,300 +574,239 -> 589,239 +219,670 -> 219,22 +512,69 -> 255,69 +83,701 -> 239,701 +874,109 -> 48,935 +980,892 -> 159,71 +154,879 -> 53,879 +782,37 -> 89,730 +481,736 -> 481,614 +377,886 -> 569,694 +777,403 -> 726,454 +728,952 -> 728,972 +495,643 -> 879,643 +425,564 -> 187,326 +443,110 -> 386,167 +529,279 -> 529,103 +985,983 -> 16,14 +145,112 -> 877,844 +914,34 -> 121,827 +409,229 -> 784,229 +719,86 -> 479,86 +929,984 -> 218,984 +985,928 -> 299,242 +168,159 -> 168,743 +189,784 -> 189,498 +401,58 -> 390,58 +47,283 -> 452,688 +246,292 -> 246,461 +869,901 -> 643,675 +879,593 -> 108,593 +707,417 -> 336,417 +99,401 -> 99,502 +583,764 -> 583,668 +493,934 -> 493,78 +643,570 -> 643,990 +278,765 -> 600,443 +940,437 -> 940,488 +812,896 -> 812,594 +727,711 -> 25,711 +173,586 -> 667,92 +169,879 -> 466,582 +361,650 -> 361,276 +725,818 -> 725,662 +48,119 -> 781,852 +921,62 -> 921,647 +135,613 -> 135,295 +702,969 -> 194,461 +306,709 -> 274,709 +117,182 -> 117,856 +608,635 -> 608,854 +448,250 -> 448,641 +635,552 -> 341,552 +528,432 -> 51,432 +711,763 -> 987,487 +43,931 -> 917,57 +980,841 -> 526,387 +279,412 -> 377,412 +334,107 -> 509,282 +164,15 -> 164,345 +708,139 -> 708,846 +323,930 -> 323,282 +256,902 -> 922,236 +586,453 -> 244,111 +21,92 -> 840,911 +282,888 -> 839,331 +278,439 -> 712,873 +110,595 -> 696,595 +95,531 -> 804,531 +800,206 -> 800,881 +396,244 -> 396,441 +334,60 -> 122,60 +640,331 -> 640,467 +757,126 -> 731,126 +430,245 -> 932,245 +160,655 -> 753,62 +502,432 -> 751,432 +434,378 -> 434,287 +907,374 -> 552,729 +548,864 -> 632,864 +616,961 -> 746,831 +116,316 -> 666,866 +78,44 -> 950,916 +873,570 -> 355,570 +202,859 -> 885,176 +449,348 -> 904,348 +143,179 -> 760,796 +478,823 -> 478,55 +790,446 -> 790,257 +34,888 -> 736,888 +630,696 -> 437,889 +350,589 -> 118,821 +803,373 -> 808,373 +490,778 -> 818,450 +487,725 -> 487,836 +794,502 -> 794,114 +136,743 -> 136,634 +572,103 -> 194,103 +488,614 -> 528,614 +18,878 -> 539,357 +889,35 -> 889,271 +436,419 -> 21,419 +422,319 -> 422,821 +176,935 -> 923,188 +398,398 -> 436,436 +327,45 -> 820,538 +643,428 -> 890,675 +743,714 -> 143,114 +203,359 -> 189,359 +346,672 -> 346,190 +263,804 -> 263,249 +93,683 -> 93,453 +19,180 -> 238,399 +47,941 -> 888,100 +525,888 -> 236,599 +624,397 -> 126,397 +382,119 -> 382,981 +972,753 -> 336,117 +682,978 -> 48,344 +639,477 -> 639,408 +545,966 -> 12,966 +275,234 -> 401,234 +912,20 -> 101,20 +54,109 -> 809,864 +242,149 -> 242,283 +664,353 -> 828,353 +117,539 -> 26,630 +794,554 -> 624,554 +828,536 -> 43,536 +746,717 -> 746,420 +540,930 -> 224,930 +862,229 -> 862,212 +492,917 -> 835,574 +960,496 -> 960,618 +148,530 -> 148,485 +415,974 -> 494,974 +694,118 -> 654,158 +672,210 -> 672,81 +548,692 -> 668,812 +891,50 -> 10,931 +639,652 -> 844,652 +579,522 -> 556,545 +231,880 -> 170,880 +443,12 -> 443,775 +562,185 -> 562,984 +619,313 -> 74,858 +371,502 -> 642,231 +969,694 -> 714,949 +943,157 -> 179,921 +821,305 -> 821,427 +782,579 -> 874,671 +378,943 -> 378,956 +315,636 -> 572,893 +544,357 -> 315,357 +51,158 -> 16,158 +151,428 -> 508,428 +818,939 -> 90,939 +99,396 -> 451,396 +602,834 -> 695,834 +974,145 -> 974,919 +327,630 -> 254,630 +858,166 -> 900,166 +537,681 -> 564,681 +672,674 -> 672,619 +544,408 -> 750,614 +84,664 -> 210,664 +204,886 -> 469,886 +475,940 -> 475,592 +868,922 -> 614,922 +987,939 -> 367,939 +854,498 -> 956,498 +863,148 -> 22,989 +565,580 -> 948,197 +231,952 -> 798,385 +935,832 -> 113,10 +631,362 -> 631,329 +405,143 -> 303,143 +807,831 -> 891,831 +450,976 -> 450,247 +488,676 -> 508,676 +170,328 -> 636,794 +626,815 -> 626,938 +217,558 -> 708,558 +598,549 -> 532,549 +824,307 -> 304,307 +539,932 -> 390,932 +542,786 -> 435,893 +735,42 -> 389,388 +677,448 -> 65,448 +929,915 -> 29,15 +870,344 -> 870,287 +187,138 -> 754,138 +729,353 -> 508,132 +919,821 -> 317,219 +272,459 -> 272,72 +599,413 -> 342,413 +919,862 -> 199,142 +229,476 -> 893,476 +438,516 -> 150,228 +914,132 -> 173,873 +905,815 -> 315,815 +766,136 -> 766,207 +548,546 -> 451,643 +836,231 -> 381,231 +484,854 -> 852,854 +736,209 -> 307,209 +751,156 -> 809,156 +659,937 -> 659,333 +74,899 -> 485,488 +843,329 -> 843,584 +793,944 -> 910,827 +67,298 -> 610,841 +43,15 -> 960,932 +633,527 -> 912,806 +782,246 -> 716,312 +30,46 -> 912,928 +473,833 -> 473,189 +903,506 -> 61,506 +85,404 -> 85,898 +944,682 -> 944,465 +420,695 -> 391,666 +560,110 -> 810,360 +246,368 -> 25,368 +399,397 -> 781,15 +452,618 -> 452,340 +467,854 -> 890,854 +77,314 -> 77,780 +523,501 -> 523,646 +67,284 -> 637,284 +88,13 -> 988,913 +173,20 -> 844,691 +667,821 -> 722,821 +384,840 -> 792,432 +270,36 -> 270,352 +311,16 -> 311,334 +736,900 -> 736,264 +613,827 -> 748,962 +41,81 -> 885,925 +408,884 -> 756,884 +380,612 -> 402,634 +82,645 -> 82,708 +934,331 -> 316,331 +634,116 -> 634,891 +942,56 -> 942,642 +441,260 -> 955,774 +925,980 -> 314,369 +317,893 -> 577,893 +362,137 -> 433,137 +434,928 -> 434,623 +819,18 -> 819,488 +185,348 -> 615,778 +895,357 -> 492,357 +742,645 -> 742,151 +522,855 -> 366,699 +867,390 -> 57,390 +95,566 -> 389,272 +887,793 -> 887,871 +351,251 -> 351,30 +309,448 -> 865,448 +190,690 -> 70,570 +383,805 -> 383,607 +140,157 -> 140,164 +685,222 -> 705,222 +192,949 -> 192,358 +856,768 -> 856,967 +337,344 -> 771,344 +919,86 -> 53,952 +137,723 -> 887,723 +33,108 -> 873,948 +195,690 -> 195,184 +136,505 -> 136,520 +509,69 -> 509,800 +255,742 -> 255,740 +650,105 -> 650,483 +985,451 -> 268,451 +68,346 -> 171,346 +472,28 -> 574,28 +660,308 -> 660,382 +341,553 -> 341,419 +430,304 -> 807,304 +333,258 -> 795,258 +853,637 -> 252,36 +881,893 -> 237,249 +552,160 -> 826,160 +728,446 -> 728,905 +529,326 -> 529,860 +564,759 -> 564,737 +533,688 -> 78,233 +445,314 -> 329,198 +935,597 -> 652,597 +955,958 -> 174,177 +178,522 -> 178,457 +124,351 -> 74,351 +265,840 -> 451,654 +771,914 -> 771,332 +72,14 -> 72,574 +970,828 -> 197,55 +631,744 -> 631,746 +765,759 -> 119,113 +260,882 -> 262,882 +676,760 -> 61,145 +680,168 -> 959,168 +466,811 -> 466,745 +566,242 -> 566,471 +768,975 -> 768,75 +391,550 -> 391,591 +781,678 -> 771,678 +731,620 -> 951,620 +973,290 -> 973,664 +838,691 -> 835,691 +294,240 -> 378,240 +390,708 -> 908,190 +521,933 -> 963,933 +358,46 -> 919,46 +431,410 -> 431,297 +833,706 -> 330,706 +13,910 -> 876,910 +619,567 -> 619,398 +165,779 -> 165,941 +21,139 -> 21,535 +921,420 -> 358,420 +629,111 -> 608,111 +654,244 -> 654,500 +982,386 -> 982,841 +252,127 -> 144,235 +144,518 -> 144,344 +581,589 -> 130,138 +927,835 -> 882,790 +859,658 -> 320,119 +110,326 -> 110,168 +149,64 -> 917,832 +651,771 -> 897,771 +788,66 -> 231,623 +710,608 -> 370,268 +927,175 -> 778,26 +957,970 -> 53,66 +350,313 -> 350,192 +115,505 -> 129,505 +414,163 -> 182,163 +874,334 -> 532,676 +441,790 -> 441,976 +66,162 -> 226,162 +839,453 -> 310,982 +63,974 -> 132,974 +51,383 -> 297,137 +343,954 -> 262,873 +726,474 -> 637,563 +449,205 -> 449,279 +855,845 -> 722,845 +28,750 -> 33,750 +272,175 -> 212,235 +428,172 -> 710,172 +824,834 -> 824,557 +25,864 -> 855,34 +66,425 -> 84,425 +456,812 -> 456,785 +286,294 -> 73,294 +400,329 -> 525,204 +888,160 -> 888,124 +879,742 -> 761,742 +893,751 -> 858,786 +621,765 -> 10,154 +162,280 -> 162,889 +96,830 -> 646,280 +646,720 -> 250,324 +367,586 -> 695,258 +298,353 -> 566,621 +813,256 -> 813,367 +559,672 -> 471,672 +951,187 -> 234,904 +868,753 -> 80,753 +91,937 -> 803,225 +112,142 -> 18,236 +936,281 -> 936,976 +95,867 -> 753,209 +421,735 -> 833,735 +830,755 -> 963,755 +355,272 -> 355,70 +309,479 -> 309,45 +951,145 -> 676,145 +513,143 -> 713,143 +491,565 -> 988,68 +797,742 -> 596,541 +581,621 -> 277,317 +132,480 -> 101,480 +140,72 -> 375,72 +524,221 -> 897,594 +694,549 -> 179,34 +689,729 -> 689,527 +27,953 -> 27,32 +913,774 -> 913,705 +669,861 -> 669,360 +454,250 -> 454,344 +863,95 -> 13,945 +341,50 -> 341,795 +863,50 -> 212,50 +73,689 -> 143,689 +944,20 -> 31,933 +22,988 -> 873,137 +798,552 -> 798,774 +935,583 -> 935,393 +462,176 -> 986,176 +739,400 -> 972,400 +441,31 -> 441,37 +628,381 -> 628,339 +545,345 -> 615,345 +91,736 -> 373,736 +825,738 -> 825,687 +541,877 -> 541,569 +750,739 -> 390,739 +873,384 -> 873,665 +597,61 -> 385,61 +518,62 -> 229,62 +623,192 -> 502,192 +163,861 -> 732,292 +748,304 -> 873,429 +375,436 -> 375,655 +146,228 -> 146,91 +808,844 -> 243,844 +174,115 -> 982,923 +598,384 -> 598,956 +932,736 -> 843,736 +772,110 -> 883,110 +298,960 -> 852,406 +744,772 -> 693,823 +605,639 -> 731,639 +126,770 -> 732,164 +13,986 -> 988,11 +756,37 -> 756,164 +132,900 -> 984,48 +806,524 -> 331,524 +84,645 -> 84,195 +329,447 -> 939,447 +684,566 -> 793,566 +747,595 -> 747,181 +293,121 -> 430,121 +42,918 -> 826,918 +32,312 -> 833,312 +42,309 -> 42,752 +332,74 -> 736,74 +699,209 -> 495,209 +297,113 -> 297,827 +515,973 -> 515,35 +774,951 -> 774,290 +471,921 -> 919,921 +297,282 -> 297,524 +477,825 -> 477,343 +220,665 -> 351,796 +483,128 -> 376,128