5 files changed, 655 insertions, 0 deletions
diff --git a/Advent-of-Code-2021/AOC-5/build.sh b/Advent-of-Code-2021/AOC-5/build.sh
new file mode 100755
index 0000000..6be9241
--- /dev/null
+++ b/Advent-of-Code-2021/AOC-5/build.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+set -xe
+
+gcc -o main -Wall -Wextra main.c
+
+./main
diff --git a/Advent-of-Code-2021/AOC-5/example.txt b/Advent-of-Code-2021/AOC-5/example.txt
new file mode 100644
index 0000000..b258f68
--- /dev/null
+++ b/Advent-of-Code-2021/AOC-5/example.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/Advent-of-Code-2021/AOC-5/input.txt b/Advent-of-Code-2021/AOC-5/input.txt
new file mode 100644
index 0000000..04c5152
--- /dev/null
+++ b/Advent-of-Code-2021/AOC-5/input.txt
@@ -0,0 +1,500 @@
+60,28 -> 893,861
+934,945 -> 222,233
+125,246 -> 125,306
+490,255 -> 490,847
+457,868 -> 364,961
+610,46 -> 610,826
+338,711 -> 982,67
+199,581 -> 295,581
+578,489 -> 522,545
+180,516 -> 180,904
+354,363 -> 145,363
+757,471 -> 692,471
+896,71 -> 896,185
+967,744 -> 967,486
+166,19 -> 483,19
+469,22 -> 529,22
+774,311 -> 807,311
+617,308 -> 203,308
+694,405 -> 694,43
+378,176 -> 378,488
+989,189 -> 215,189
+375,96 -> 612,96
+505,467 -> 505,246
+77,832 -> 77,473
+686,879 -> 684,879
+360,593 -> 151,384
+387,322 -> 626,322
+66,784 -> 66,109
+100,411 -> 635,946
+722,14 -> 722,784
+724,751 -> 764,751
+788,844 -> 32,88
+905,799 -> 905,713
+282,502 -> 238,502
+685,259 -> 685,768
+116,578 -> 477,217
+115,78 -> 115,458
+329,569 -> 66,306
+817,815 -> 817,466
+781,909 -> 872,909
+62,44 -> 964,946
+755,307 -> 593,307
+436,56 -> 436,869
+596,815 -> 49,268
+465,986 -> 926,525
+885,254 -> 39,254
+947,433 -> 764,433
+719,787 -> 200,787
+380,461 -> 243,461
+675,434 -> 675,582
+106,548 -> 272,714
+703,143 -> 703,111
+238,745 -> 60,745
+646,235 -> 646,742
+243,439 -> 243,964
+347,763 -> 321,789
+322,294 -> 738,294
+134,361 -> 946,361
+223,30 -> 498,305
+78,721 -> 288,721
+792,875 -> 572,875
+548,380 -> 637,291
+85,417 -> 85,296
+766,81 -> 766,131
+340,218 -> 340,271
+56,962 -> 974,44
+415,940 -> 386,940
+960,60 -> 46,974
+719,527 -> 743,527
+971,986 -> 313,986
+415,316 -> 415,57
+612,556 -> 612,648
+421,776 -> 570,776
+478,533 -> 478,831
+758,304 -> 112,950
+258,950 -> 79,950
+329,349 -> 216,349
+527,38 -> 755,38
+517,239 -> 207,239
+497,944 -> 898,944
+418,642 -> 418,557
+828,750 -> 456,750
+632,916 -> 15,299
+955,973 -> 970,958
+474,524 -> 949,49
+842,690 -> 842,116
+203,267 -> 916,980
+128,562 -> 936,562
+682,963 -> 193,963
+704,822 -> 44,162
+371,309 -> 421,359
+379,240 -> 510,240
+547,177 -> 547,20
+784,968 -> 784,613
+75,138 -> 75,724
+725,48 -> 32,741
+141,674 -> 545,674
+193,922 -> 193,845
+916,831 -> 916,401
+912,232 -> 923,232
+127,911 -> 911,127
+140,381 -> 140,913
+472,243 -> 472,134
+311,548 -> 311,741
+415,590 -> 415,409
+20,984 -> 983,21
+572,575 -> 572,756
+804,188 -> 20,972
+485,104 -> 962,104
+31,966 -> 986,11
+584,473 -> 338,473
+974,962 -> 34,22
+176,279 -> 921,279
+305,863 -> 305,981
+137,889 -> 137,47
+888,259 -> 888,125
+794,774 -> 794,455
+193,118 -> 966,118
+429,302 -> 547,184
+59,49 -> 984,974
+978,56 -> 232,802
+23,142 -> 456,142
+532,574 -> 532,265
+936,263 -> 933,263
+773,856 -> 230,313
+182,809 -> 913,809
+364,958 -> 901,958
+724,290 -> 64,950
+312,967 -> 312,166
+208,286 -> 566,286
+828,907 -> 828,729
+79,692 -> 753,18
+235,601 -> 811,601
+735,206 -> 301,206
+246,112 -> 246,423
+712,439 -> 712,108
+570,179 -> 751,179
+766,22 -> 816,22
+51,686 -> 27,686
+50,954 -> 50,31
+762,413 -> 762,601
+223,812 -> 670,812
+391,882 -> 712,882
+842,332 -> 922,332
+540,88 -> 540,124
+75,312 -> 161,312
+979,984 -> 10,15
+479,856 -> 823,856
+690,491 -> 298,883
+481,401 -> 481,279
+870,942 -> 276,348
+39,935 -> 937,37
+706,275 -> 706,948
+530,892 -> 535,897
+743,223 -> 929,223
+682,917 -> 490,917
+616,268 -> 456,268
+484,72 -> 429,72
+61,365 -> 430,365
+382,741 -> 910,741
+710,406 -> 330,406
+795,770 -> 55,770
+117,416 -> 352,651
+593,151 -> 20,724
+238,556 -> 584,556
+680,583 -> 680,504
+678,440 -> 212,440
+508,222 -> 508,844
+435,873 -> 93,873
+129,607 -> 468,268
+280,147 -> 94,147
+238,872 -> 971,139
+881,339 -> 664,339
+289,960 -> 289,664
+70,762 -> 973,762
+429,24 -> 429,202
+907,785 -> 907,190
+598,548 -> 598,63
+324,220 -> 281,220
+754,980 -> 79,980
+568,508 -> 583,508
+364,712 -> 503,712
+655,963 -> 898,963
+253,359 -> 46,566
+989,989 -> 14,14
+329,924 -> 380,924
+248,826 -> 675,826
+417,428 -> 417,320
+13,12 -> 984,983
+916,53 -> 916,896
+247,285 -> 377,155
+937,588 -> 710,588
+473,270 -> 466,277
+567,74 -> 567,388
+371,470 -> 228,470
+640,96 -> 766,96
+725,499 -> 372,499
+184,561 -> 184,236
+654,446 -> 933,446
+156,153 -> 978,975
+811,228 -> 922,339
+84,861 -> 878,67
+622,329 -> 622,425
+415,186 -> 450,221
+109,488 -> 653,488
+982,16 -> 33,965
+100,885 -> 829,156
+342,914 -> 342,636
+177,323 -> 728,874
+81,414 -> 406,739
+889,79 -> 889,698
+504,450 -> 148,806
+961,33 -> 51,943
+656,21 -> 100,21
+32,60 -> 32,562
+499,174 -> 499,301
+162,740 -> 162,906
+190,183 -> 811,804
+93,960 -> 13,960
+787,681 -> 866,681
+254,332 -> 254,79
+595,873 -> 595,496
+151,737 -> 151,390
+974,429 -> 990,429
+295,784 -> 295,513
+378,942 -> 378,283
+152,838 -> 796,838
+624,630 -> 881,887
+90,420 -> 412,420
+868,69 -> 46,891
+75,890 -> 452,513
+133,460 -> 133,985
+970,145 -> 549,145
+149,462 -> 916,462
+92,845 -> 92,268
+580,99 -> 250,99
+618,708 -> 618,652
+690,948 -> 690,38
+808,594 -> 944,730
+100,359 -> 312,359
+546,392 -> 41,897
+593,413 -> 593,892
+602,484 -> 602,144
+90,863 -> 90,170
+888,987 -> 888,162
+229,932 -> 960,201
+919,654 -> 70,654
+13,684 -> 13,348
+743,477 -> 166,477
+901,113 -> 936,113
+167,567 -> 540,567
+566,729 -> 566,660
+102,660 -> 615,660
+273,241 -> 273,413
+512,241 -> 512,643
+869,695 -> 614,440
+356,583 -> 356,408
+61,345 -> 61,233
+973,33 -> 88,918
+977,130 -> 771,130
+422,382 -> 899,382
+536,517 -> 914,139
+563,755 -> 312,755
+770,581 -> 770,940
+103,186 -> 313,186
+681,490 -> 77,490
+676,351 -> 913,588
+292,700 -> 862,700
+445,175 -> 188,175
+62,490 -> 173,601
+530,455 -> 63,455
+145,85 -> 832,772
+273,414 -> 273,240
+25,888 -> 25,684
+599,393 -> 599,232
+198,296 -> 584,682
+217,886 -> 614,886
+464,598 -> 362,496
+874,106 -> 874,227
+248,511 -> 940,511
+501,861 -> 21,381
+385,232 -> 341,232
+258,449 -> 337,449
+94,46 -> 910,862
+946,825 -> 946,341
+93,836 -> 93,781
+170,903 -> 616,457
+717,333 -> 717,238
+404,243 -> 516,243
+611,579 -> 217,973
+76,851 -> 76,255
+181,780 -> 661,780
+316,188 -> 333,188
+799,92 -> 779,92
+955,374 -> 869,374
+872,792 -> 280,200
+337,239 -> 438,239
+424,706 -> 273,857
+501,239 -> 684,239
+198,671 -> 882,671
+790,775 -> 802,775
+708,624 -> 361,277
+547,731 -> 547,621
+264,449 -> 293,449
+496,870 -> 496,396
+988,959 -> 988,285
+19,51 -> 926,958
+472,537 -> 127,882
+188,488 -> 478,198
+949,376 -> 797,224
+448,609 -> 348,609
+838,285 -> 838,865
+796,142 -> 70,868
+848,91 -> 972,91
+722,964 -> 722,409
+313,156 -> 313,725
+925,251 -> 925,687
+803,815 -> 113,125
+505,517 -> 505,337
+935,920 -> 235,920
+674,274 -> 63,885
+458,981 -> 626,981
+928,950 -> 836,950
+163,453 -> 695,985
+57,374 -> 398,374
+937,327 -> 937,811
+975,932 -> 265,222
+490,583 -> 490,482
+170,183 -> 196,183
+738,978 -> 738,812
+914,170 -> 914,202
+202,885 -> 499,885
+270,887 -> 150,887
+447,783 -> 831,399
+66,136 -> 77,136
+536,703 -> 662,829
+297,821 -> 297,792
+640,572 -> 321,572
+244,833 -> 865,212
+454,672 -> 454,726
+133,812 -> 303,642
+280,589 -> 184,589
+977,572 -> 977,42
+62,247 -> 215,247
+427,503 -> 809,885
+671,85 -> 671,770
+296,990 -> 296,558
+103,19 -> 971,887
+263,712 -> 263,329
+954,897 -> 954,41
+278,536 -> 278,346
+270,620 -> 983,620
+229,863 -> 91,863
+935,413 -> 394,413
+709,668 -> 77,668
+310,853 -> 310,286
+534,694 -> 511,717
+349,726 -> 349,439
+113,196 -> 970,196
+836,340 -> 709,340
+38,485 -> 38,14
+38,278 -> 569,278
+862,90 -> 281,671
+677,124 -> 405,124
+399,568 -> 536,705
+611,839 -> 188,416
+570,925 -> 570,251
+804,368 -> 284,888
+262,842 -> 388,842
+751,800 -> 751,504
+762,882 -> 201,321
+411,421 -> 807,421
+654,406 -> 265,795
+863,558 -> 625,320
+451,673 -> 451,354
+359,239 -> 566,239
+259,211 -> 955,907
+253,506 -> 542,217
+547,794 -> 373,620
+132,263 -> 581,712
+168,237 -> 168,142
+834,296 -> 152,978
+156,14 -> 955,14
+927,22 -> 285,664
+384,291 -> 362,269
+91,561 -> 91,19
+472,953 -> 472,576
+700,666 -> 723,689
+447,815 -> 566,815
+698,411 -> 698,762
+427,606 -> 119,298
+531,401 -> 669,263
+681,21 -> 681,111
+168,360 -> 168,447
+74,67 -> 717,67
+287,88 -> 345,88
+234,80 -> 234,848
+583,251 -> 33,251
+200,522 -> 366,356
+815,936 -> 27,148
+139,302 -> 139,768
+473,69 -> 473,664
+42,813 -> 42,918
+881,188 -> 881,345
+457,920 -> 301,764
+894,662 -> 779,662
+750,411 -> 750,368
+986,167 -> 246,167
+914,418 -> 742,590
+710,110 -> 63,757
+353,493 -> 353,473
+211,700 -> 181,700
+492,604 -> 25,604
+212,174 -> 362,174
+801,434 -> 752,385
+956,861 -> 469,374
+197,318 -> 257,378
+604,594 -> 604,809
+716,447 -> 306,857
+974,974 -> 24,24
+925,467 -> 925,311
+357,381 -> 769,381
+714,395 -> 372,395
+360,718 -> 728,718
+161,186 -> 730,755
+407,316 -> 407,61
+466,214 -> 333,347
+190,955 -> 190,678
+969,48 -> 72,945
+296,153 -> 833,153
+930,400 -> 637,400
+606,953 -> 541,953
+978,179 -> 21,179
+112,49 -> 112,793
+346,881 -> 151,881
+737,404 -> 737,693
+98,271 -> 98,144
+469,830 -> 46,830
+246,651 -> 246,243
+47,129 -> 880,962
+449,609 -> 980,78
+603,307 -> 603,896
+121,339 -> 22,240
+97,726 -> 274,726
+527,668 -> 786,409
+649,162 -> 321,162
+253,10 -> 253,690
+43,748 -> 590,748
+245,424 -> 245,495
+509,595 -> 261,843
+924,758 -> 683,758
+693,516 -> 684,507
+654,201 -> 654,840
+321,543 -> 315,549
+840,309 -> 764,233
+865,183 -> 177,871
+700,135 -> 14,821
+178,178 -> 971,971
+88,649 -> 88,899
+327,37 -> 327,58
+252,687 -> 482,457
+12,771 -> 754,29
+309,695 -> 630,695
+146,671 -> 146,695
+226,697 -> 798,697
+239,736 -> 239,945
+483,756 -> 483,965
+306,475 -> 800,969
+580,927 -> 580,102
+867,83 -> 830,83
+635,359 -> 761,233
+733,851 -> 180,298
+478,76 -> 401,76
+552,581 -> 552,525
+842,724 -> 847,724
+652,76 -> 385,76
+695,894 -> 245,894
+301,487 -> 301,665
+412,555 -> 412,80
+591,311 -> 289,311
+961,933 -> 69,41
+78,266 -> 14,202
+255,696 -> 766,696
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+866,377 -> 652,591
+267,226 -> 204,163
+506,104 -> 506,587
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+879,127 -> 879,859
+65,669 -> 65,747
+486,745 -> 612,745
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+41,840 -> 226,655
+207,495 -> 94,495
+142,970 -> 285,970
+73,239 -> 83,239
+787,409 -> 527,409
+678,565 -> 678,582
+314,185 -> 67,185
diff --git a/Advent-of-Code-2021/AOC-5/main b/Advent-of-Code-2021/AOC-5/main
new file mode 100755
index 0000000..c4629f0
--- /dev/null
+++ b/Advent-of-Code-2021/AOC-5/main
diff --git a/Advent-of-Code-2021/AOC-5/main.c b/Advent-of-Code-2021/AOC-5/main.c
new file mode 100644
index 0000000..ea39e06
--- /dev/null
+++ b/Advent-of-Code-2021/AOC-5/main.c
@@ -0,0 +1,138 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+#if 0
+#define PART_1
+#else
+#define PART_2
+#endif
+
+#if 0
+#define FILE_PATH "example.txt"
+#define WIDTH  10
+#define HEIGHT 10
+#else
+#define FILE_PATH "input.txt"
+#define WIDTH  10000
+#define HEIGHT 10000
+#endif
+
+int board[WIDTH][HEIGHT] = {0};
+
+void draw_line(int x1, int y1, int x2, int y2)
+{
+    if(x1 == x2)
+    {
+        for(int y = MIN(y1, y2); y <= MAX(y1, y2); y++)
+            board[x1][y]++;
+
+    }
+    else if(y1 == y2)
+    {
+        for(int x = MIN(x1, x2); x <= MAX(x1, x2); x++)
+            board[x][y1]++;
+    }
+#ifdef PART_2
+    else
+    {
+        int direction_x = (x1 < x2) ? 1 : -1;
+        int direction_y = (y1 < y2) ? 1 : -1;
+
+        int y = y1;
+        int x = x1;
+        while(!((y == y2) && (x == x2)))
+        {
+            board[x][y]++;
+            x+=direction_x;
+            y+=direction_y;
+        }
+    }
+#endif
+}
+
+void parse()
+{
+    FILE *fp = fopen(FILE_PATH, "r");
+    if(!fp) {
+        fprintf(stderr, "ERROR: Could not open file: %s", FILE_PATH);
+        exit(EXIT_FAILURE);
+    }
+
+    char *vec1, *vec2;
+    char line[256];
+    while(fgets(line, sizeof(line), fp) != NULL)
+    {
+        vec1 = strtok(line, " -> ");
+        vec2 = strtok(NULL, " -> ");
+
+        int x1, y1, x2, y2;
+        x1 = atoi(strtok(vec1, ","));
+        y1 = atoi(strtok(NULL, ","));
+        x2 = atoi(strtok(vec2, ","));
+        y2 = atoi(strtok(NULL, ","));
+
+        draw_line(x1, y1, x2, y2);
+    }
+}
+
+void print_board()
+{
+    for(int i = 0; i < HEIGHT; i++)
+    {
+        for(int j = 0; j < WIDTH; j++)
+        {
+            if(board[j][i] == 0)
+                putc('.', stdout);
+            else if(board[j][i] == 1)
+                putc('#', stdout);
+            else
+                putc('@', stdout);
+        }
+        putc('\n', stdout);
+    }
+}
+
+void part_1()
+{
+    parse();
+
+    int count = 0;
+    for(int i = 0; i < HEIGHT; i++)
+        for(int j = 0; j < WIDTH; j++)
+            if(board[j][i] >= 2) count++;
+
+    printf("Count is %d\n", count);
+}
+
+void part_2()
+{
+    parse();
+
+    int count = 0;
+    for(int i = 0; i < HEIGHT; i++)
+        for(int j = 0; j < WIDTH; j++)
+            if(board[j][i] >= 2) count++;
+
+    // print_board();
+
+    printf("Count is %d\n", count);
+}
+
+int main(void)
+{
+
+#ifdef PART_1
+    part_1();
+#endif
+
+#ifdef PART_2
+    part_2();
+#endif
+
+    return 0;
+}