Committing days 1-4

2023-12-04 19:40:03 -05:00
commit db9b6acbb6
19 changed files with 2500 additions and 0 deletions
--- a/03/03-part2.c
+++ b/03/03-part2.c
@@ -0,0 +1,158 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define STRBUF_SIZE     200
+#define DEFAULT_FILE    "input.txt"
+#define ISDIGIT(X)      (X >= '0' && X <= '9')
+
+// Parses a found number.
+// The provided location can be any digit of the
+// number; this function will automatically
+// seek the first digit before processing.
+// Erases numbers as they are processed.
+uint16_t parse_num_at(char *str, uint8_t idx)
+{
+
+    // Check input
+    if (str[idx] < '0' || str[idx] > '9') return 0;
+
+    // Find first digit of number
+    while (ISDIGIT(str[idx]) && idx) idx--;
+    if (!ISDIGIT(str[idx])) idx++;
+
+    uint16_t num = 0;
+
+    // Add up all digits
+    while (ISDIGIT(str[idx]))
+    {
+        num = (num * 10) + (str[idx] - '0');
+        // Erase the number to make sure we don't count it twice
+        str[idx] = '.';
+        idx++;
+    }
+
+    return num;
+}
+
+// If the character is a * with two adjacent numbers,
+// returns the gear ratio. Returns zero if the symbol
+// is not a gear.
+uint64_t get_gear_ratio( uint8_t idx,
+                                char *above,
+                                char *current,
+                                char *below)
+{
+    char *above_copy =   malloc(sizeof(char) * STRBUF_SIZE);
+    char *current_copy = malloc(sizeof(char) * STRBUF_SIZE);
+    char *below_copy =   malloc(sizeof(char) * STRBUF_SIZE);
+
+    memcpy(above_copy, above, STRBUF_SIZE);
+    memcpy(current_copy, current, STRBUF_SIZE);
+    memcpy(below_copy, below, STRBUF_SIZE);
+
+    uint16_t nums[8] = {0};
+
+    if (idx) nums[0] = parse_num_at(above_copy, idx - 1);
+    nums[1] = parse_num_at(above_copy, idx);
+    nums[2] = parse_num_at(above_copy, idx + 1);
+
+    nums[3] = parse_num_at(current_copy, idx + 1);
+    nums[4] = parse_num_at(current_copy, idx - 1);
+
+    if (idx) nums[5] = parse_num_at(below_copy, idx - 1);
+    nums[6] = parse_num_at(below_copy, idx);
+    nums[7] = parse_num_at(below_copy, idx + 1);
+
+    free(above_copy);
+    free(current_copy);
+    free(below_copy);
+
+    uint8_t i = 0;
+    uint16_t num1 = 0;
+    uint16_t num2 = 0;
+
+    for (i = 0; i < 8; i++)
+    {
+        // More than 2 adjacent numbers
+        if (nums[i] && num1 && num2) return 0;
+
+        // The second number
+        if (nums[i] && num1) num2 = nums[i];
+
+        // The first number
+        else if (nums[i]) num1 = nums[i];
+    }
+
+    return num1 * num2;
+}
+
+// Search through a line of *current for symbols.
+uint64_t parse_line(char *above, char *current, char *below)
+{
+    uint64_t sum = 0;
+    uint8_t idx;
+    char c;
+
+    for (idx = 0; current[idx] != 0; idx++)
+    {
+        c = current[idx];
+        if (c == '*')
+        {
+            // We've found a symbol,
+            // add up all numbers around it
+            sum += get_gear_ratio(idx, above, current, below);
+        }
+    }
+    
+    return sum;
+}
+
+int main(int argc, char **argv)
+{
+    // Get filename as an argument, defaults to "input.txt"
+    char *path = (argc > 1) ? argv[1] : DEFAULT_FILE;
+
+    if (!path)
+    {
+        printf("Requires input file.\n");
+        return 1;
+    }
+
+    FILE *file = fopen(path, "r");
+
+    if (!file)
+    {
+        printf("Could not find file.");
+        return 1;
+    }
+
+    char *above =   malloc(sizeof(char) * STRBUF_SIZE);
+    char *current = malloc(sizeof(char) * STRBUF_SIZE);
+    char *below =   malloc(sizeof(char) * STRBUF_SIZE);
+
+    memset(above, '.', STRBUF_SIZE);
+    fgets(current, STRBUF_SIZE, file);
+
+    uint64_t sum = 0;
+
+    while (fgets(below, 200, file))
+    {
+        sum += parse_line(above, current, below);
+
+        free(above);
+        above = current;
+        current = below;
+        below = malloc(sizeof(char) * STRBUF_SIZE);
+        memset(below, '.', STRBUF_SIZE);
+    }
+
+    // Process the last line of the file
+    sum += parse_line(above, current, below);
+
+    printf("Sum: %lud\n", sum);
+
+    return 0;
+}
--- a/03/03.c
+++ b/03/03.c
@@ -0,0 +1,130 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define STRBUF_SIZE     200
+#define DEFAULT_FILE    "input.txt"
+#define ISDIGIT(X)      (X >= '0' && X <= '9')
+
+// Parses a found number.
+// The provided location can be any digit of the
+// number; this function will automatically
+// seek the first digit before processing.
+// Erases numbers as they are processed.
+uint16_t parse_num_at(char *str, uint8_t idx)
+{
+
+    // Check input
+    if (str[idx] < '0' || str[idx] > '9') return 0;
+
+    // Find first digit of number
+    while (ISDIGIT(str[idx]) && idx) idx--;
+    if (!ISDIGIT(str[idx])) idx++;
+
+    uint16_t num = 0;
+
+    // Add up all digits
+    while (ISDIGIT(str[idx]))
+    {
+        num = (num * 10) + (str[idx] - '0');
+        // Erase the number to make sure we don't count it twice
+        str[idx] = '.';
+        idx++;
+    }
+
+    return num;
+}
+
+// Returns the sum of all numbers around a symbol,
+// including diagonals.
+uint16_t search_numbers_around( uint8_t idx,
+                                char *above,
+                                char *current,
+                                char *below)
+{
+    uint16_t sum = 0;
+    if (idx) sum += parse_num_at(above, idx - 1);
+    sum += parse_num_at(above, idx);
+    sum += parse_num_at(above, idx + 1);
+
+    sum += parse_num_at(current, idx + 1);
+    sum += parse_num_at(current, idx - 1);
+
+    if (idx) sum += parse_num_at(below, idx - 1);
+    sum += parse_num_at(below, idx);
+    sum += parse_num_at(below, idx + 1);
+
+    return sum;
+}
+
+// Search through a line of *current for symbols.
+// returns the sum for that line (erases numbers as
+// they are processed.)
+uint16_t parse_line(char *above, char *current, char *below)
+{
+    uint16_t sum = 0;
+    uint8_t idx;
+    char c;
+
+    for (idx = 0; current[idx] != 0; idx++)
+    {
+        c = current[idx];
+        if (!ISDIGIT(c) && c != '.' && c != '\n')
+        {
+            // We've found a symbol,
+            // add up all numbers around it
+            sum += search_numbers_around(idx, above, current, below);
+        }
+    }
+    
+    return sum;
+}
+
+int main(int argc, char **argv)
+{
+    // Get filename as an argument, defaults to "input.txt"
+    char *path = (argc > 1) ? argv[1] : DEFAULT_FILE;
+
+    if (!path)
+    {
+        printf("Requires input file.\n");
+        return 1;
+    }
+
+    FILE *file = fopen(path, "r");
+
+    if (!file)
+    {
+        printf("Could not find file.");
+        return 1;
+    }
+
+    char *above =   malloc(sizeof(char) * STRBUF_SIZE);
+    char *current = malloc(sizeof(char) * STRBUF_SIZE);
+    char *below =   malloc(sizeof(char) * STRBUF_SIZE);
+
+    memset(above, '.', STRBUF_SIZE);
+    fgets(current, STRBUF_SIZE, file);
+
+    uint32_t sum = 0;
+
+    while (fgets(below, 200, file))
+    {
+        sum += parse_line(above, current, below);
+
+        free(above);
+        above = current;
+        current = below;
+        below = malloc(sizeof(char) * STRBUF_SIZE);
+        memset(below, '.', STRBUF_SIZE);
+    }
+
+    // Process the last line of the file
+    sum += parse_line(above, current, below);
+
+    printf("Sum: %d\n", sum);
+
+    return 0;
+}
--- a/03/input.txt
+++ b/03/input.txt
@@ -0,0 +1,140 @@
+.854...........................................................................362...........271...732........838.........24................
+...*.............................117*...........459........767*648....#.........*...................................$...&..=................
+....970.........368.124.+............57................653...........723.....366....*443..60.........536....441....45..879.....789...*......
+...........749*...-...+..330.....................215%...*................725.....953........%.................*............639......331.419.
+.......706.....59.............*....=...262.............678...........857.*............189....................912.+589.846*...*..............
+..........*................393.59..418....*................151...........594...........*....584*258.......................17.997............
+.......774....275........................777........841..............988.........121....908.........86.....482..295....................@....
+.110..........%.....605..@.......305*18...............*....740.............840..*................52*.......*...........100...........250....
+...........*..............856..............412.........761....*....344....*.....505.....................121......709...-....-...............
+......980.269..189+............701..............22...$........343..*...684..............-375......223........97.*..........890......443.....
+..904*..................555.....*.......38.....*....207............773.......................824.....*.......*..../....618..................
+....................355*........362....*......442.$..........613...........%770.......526.....*.......418.....283..76....*....862...........
+...450....*292..............735.....149...........143..........*...458...........279.........43..769...................$..48.....*..........
+....*..413.........983*....*.................679.......642....214...#........107*......=.........*.....%...........276.39......196.889*624..
+...128.................658.515...890#...................../...........................60..../....528..359.....451...*.....56................
+...................719...................525.................$502............284-........@...489.................#..287.....@....+..........
+...849...............*................../.........................282.+649...............217............240.....................833.....930.
+.......666...179.....986.526................./927......73.....176*...............@...459...........=946..*..488...126.....*.................
+..........@.....*549.....@...261.....370*951...........+.............114......170.......@...............269............471.891.$859.........
+.............................../.................646.....-.327........*..237..............452......../......*620..713...............324.....
+..................=716.....753....................-....431..=.......692.%.......210.......*.......860....208...............81*655....$......
+......298....17*..........+....................................................*..........603................950.218.$......................
+................692...54......+778.809........140..*.........249............%.332..............*.........372*......*.328.....=..............
+.......421.............#..............+........*....493.......*..........589..................286...............254..........458...672...258
+........*.....949.630.....725...609.........408.............108..............304.517......829.........666*..........724.182...........*.=...
+.........435./....*..........*.*................580..................@.........*..&..147.-......221*......544..662/....*...........881......
+..750.............561......568.487.@...935.......*....106...........104......808.......*............333...................&900..............
+...................................287.$......930.....&.....*528.........332............755..................840../.............583.....209.
+.371.299.................503.............................632................*.......&...................500........647..193.......-.........
+....*........-902..2.123..*...912.......775......./...............241........734....90.968.513..66.566...................*..&...............
+..................*....@.923...*.......*.....289..47.....785..710.......54................*......*....................767....452....=....597
+.............348.362............607.....889.....#........*....*........*......$904................694...............................241.....
+....955........*.....559*792............................307..25.........449..............*751.404.....134.....841...........................
+......&.959...300............446.504.644....692...............................#.................-.....*.......*...758*35....................
+.908$...*...........&..861...........=.....%....240............-..+..9.514...615.....&....-646.....538...144.751...........899.........545..
+.......806.270*....946.@...............*..........*.555@....803..322.-............410..........514.................510..10..*.....858..-....
+...............373....................7.918.....699.........................710.......&...........-.....78%............+....34..............
+....653...............................................553.......896.......-......&...721....970.............................................
+.......%...........379..377.....770@.................$.....126....*...712.287....951.........*......984*..........+.............+700........
+..............924...*....*.............422...................*...233.*........................124...........902....181......................
+................&....156..363.....*855....*.................884......509..879..755.......$...........*635......*........283.........661.....
+..559..........................393.........766...789.............683..................461..#......910.........904.........$.%......*.....13.
+.........=...568.........680/.......................*......*522.#..........................747...........*113................702...952......
+....*....334...*...392..........910*...............233..189.........219.879............225......521...941...................................
+.146.981......284.*.......*972......391.....789*...................................628*.....*....*................675.......................
+..................921..151......................983...............582......983.690.......213.137.268.............*..............24$.........
+....561....................600........106-...............226..................*.....996.............................681.....768.......852...
+..............................%............................$................=...963..$.....@............421*305.......*.....*........$......
+.....923.285*.....961...........*......$812......812..851.............678.29.......*......501.....228..............385...853...........251..
+.444*...............*...998...99.711.............+.....*......330.....*.........287...........781..+..........%445..........................
+......$....250=.....965...*.............................113...$......766....$.......941........-......658.............894........351........
+......335...............463.328*.....411....%.............................981.113......*5.............*...773=.573&....*............$.......
+..........%348..................460.....*5..517.......583.261.....889@.......................953.....496...............547............620...
+...299.................367.......................+....*................852.442.796.........*.@...............=................834.....*.....
+....*....772...487.......................#......938.462.956..41.643...*.....#.....*592....66...809.368..3..549........................772...
+.566........*.....*320.....498..775.230.193....................*......961.........................*....*.......%283.....406.......495.......
+........292..585..............*.*.....*..........213...*309...................469..549......413........903................*....29..*........
+.........*.......@.........551..806...489......................51.655.999*.......*.$.............21*.................300..931....*..595.....
+......878......62../...........................871......169..=..&..*......235..788...497..........................68....*.......191.........
+.144.........+.....31............-...............*..623*....428.....955...............*.............424....89....*......728.............*665
+.............447...............530...203...955.336..........................227........665.......$.........*.....669..............473.......
+835...................*323..............*./...........=.....24..........*.........................452.......9.............263.........570...
+......568...803@.....................152.......209.933.....*....877..667.895............548...963......................................*....
+.......$.........=............................*...........948..-...................171.*........*.605.765..-........90..............992.....
+..360..........#.476...........................564../.............755*...............+..709...11.....*......909..........696..124%..........
+........74...73................320.........658......739...=...........484...860*....................................314.....................
+...=509...*.........79.290........*...222...*.............46...940..............960.....473.....320..........$681......*591..269....../.....
+........887.94@......*..*.........302...+.784.554+............+......#......455........./............891..........457........*...609.120....
+....................874.246.....................................+.....228..*....&.........272....%..$.....*377.....*..52..604....%..........
+.....44.....870*457................905.45......58...............956.........935.551...807..$.....21....356.......317....................%...
+.........=...................267......*...300=.........543..............398..............#.................$.......................386...745
+..........145......+............................*......*...........7....$.............64...........646....675..1..930..770.....791.$........
+................744....462......443&......*389..575..965...805....+..14.......761*578..-...#..776...*..................-........-.......822.
+....668.484...............*............875.................*.........*....................227...*..908.............215......*.......270.....
+.......*......771..........318....883......881...........655.@26..130..799.......876..91......28...........699.........807...510............
+.............-........391*.........*.......+......903..................*.....379.*....@...........713........#............*.................
+..........+................196..230...........411....*965..682.......873....$.....916....755....&..=.....................296......+958.983..
+...*.....718.......279........%...............................*.271.............@.......*......932.......621..637.843..................*....
+..59..........%2...........................................400...*...142.870...746......256..........865*...........%...=.....%...409...761.
+............@...........122*157...........394........%.444.....207...-......*.........................................434..827...*..........
+.....266..19.....=..............624.......*........398....*................373...........418...16.....654.878*.................890..........
+...............487..........884....*......199.227........723......914*411...........228..........%...................872................-...
+.....937..608.................*....306........$....................................*..................522..309.@16.....*.............765....
+......#....................128../.................%136....140.................773...114...........33....*....*.........615.....303..........
+.249.....590..$...949..768.......380......%...996..............833...28...310.#...................*..338.....770...559......................
+...+.854.../.678..*....................646...*.........................=...&..............#.....422...................#.231...714.122.......
+......*...........552........................741..........+.......437........455*768..134..69..........*........519.......*........*........
+.......976.............466......497$.............607......783........*....*.............@..............28........-.........279......394.....
+............%....857...*....542.........915.543..$...............979...581.66......555....................331...................281.........
+....715......542..#..20....@........241...*...*.........701.......$...........113...../...193..96*305........&................/...#...489...
+219*...................................#.599...845.....*.....................$....*.........*...................$....996...240........*.....
+..........151.520...554.............................665..........................1.398.=450..426.....198.....326.....+..........-....129....
+.........*...........*.................687..............588....62..........504................................................970...........
+..........463.....776......804............*..............*.....*..........%....90/...834.790...514...740.770.......667......................
+....392..................................371...184........906.56....575.............*.............*.........*......*......435.....308.......
+....*..........*......908..........497...........................-.........884....849............374.....620....727......&........../.......
+.125........862.326......&........+..........497.....&811.......213.......*...........465....................64.....993.....................
+......................%.....288...............*...-.......617...........-..677........*.....32..........-907.+........*.....=....48.475.....
+.........787.........400.....*.......420....884.425......*.....420...727........#27..181.....*....414..............986......114./.....#..404
+........*.......%...........596....=.*....................863................$................428..*......899.....................114.......
+.595=.112.737.699................382.888..........................315...@...325..........480........115..*.........-......368...............
+...........*......+.@......652.*...............................&.....@..182.......219$.........945+.............844...........996....744*...
+..87......749..535...395..#....339..564.....813....410.........135...........330.......828...........585......................*..........870
+...+........................$........+..967*.........*....921......321......%................612@....*......................44..............
+.......764...716............818..327..............578.......*...../...........941..................736..@421........762.........282.........
+861#......*..@.......982..........*.........+...............714.................*..867.....863........................@....614....=.........
+........549................*....260.........91................................85.....$........*.803*895..622.$..............*.........684...
+............770*346.....714.652......145.........270...286..........#.......................66..........*.....337.176.813...483...223*......
+..........................................*..392..&.........505...957.@.........158...285......881#....497.........+...*....................
+.........=../..../.....588........227....639............741*..........443..681..........+..153........................335...................
+........201.671.96......$............*.....................................*........415.......*........-.......155...........848.58&........
+............................922......92...........180..........................&39...%....208..389......696.....*............=.......883.852
+....237.........950.........*............80..............................................*....................657.......................*...
+....../..611.......*.....671...443...971.&....366....381...442....458...$.......589.343.397.....463.......60.......&........125......&......
+..853...../..945..564...........*......*.......@......-................783..........*.......................*.......28......=.........373...
+................*.......+843..550..998.973.........+.....208.565..@..............231......292............+.365..172............+............
+......117......615..................*............299............&..862.895............/86...*....114..552........*...697.....733...388......
+.....................................212..261........885...............*...903..26*..........50.....-..........158................*.........
+...../........11..360....748......................67....*272.....320...16.....*....137.905......239......470......................433.......
+...141........*.....%......+......967........-...%...........243...*.......904............*....*..............88.377......619...............
+................=.....-668....%.....=.+461..525.....662.....*......196..28..............778...940..400..682...*...*.........*..638*.........
+779#..113........209...........744....................*...144..811....../...#......................-...*.....297..713.....50................
+.........$................#.........844...6...........62.......*.............957...&.......112@.......211.............173....989............
+..749.......$......989..931................*....&............424.........709.......867............590...................*.......*..645......
+...*..290...573......*............437....227.....53......132............#....471%.............501..%..................733.....270.....=.....
+..637...*............596............................=....*.......400...............*...........*....................................#.......
+......958.....757%.........=.........228......624...746.81../.....*........../..718.198..38...184..............*820..774......./830.693.....
+.........................453...405.=...=....................100.144.......728...........*...................498............$................
+..616............................*.756...310.........#52.............130.......=........506.....509.779..........723.......182..+...........
+...*....49.....-..............551..........*................789./.....*......306...613........./......*..491....*...............791..931....
+...863.....%.72......832.653........*490....814.....984.....=...741...568..........*.................998........567........+........#.......
+.........171..........*..-.......406...............*....389.....................486.....630............../...............457.576............
+..............308..515..................373@......709..&..............*185..................689..........751........44..........*764........
+..............*..............661....=.........*.............993....984.....*.......908......=...273............../.*........................
+.......582..335...260....59......998../.....39.760.313*174...*..........@.183......................*47....&994.887.577........*464.....22...
+......*...............................449..................802........762.....522..139+..154..266$......................46.323.....712*.....
+....827.....................................35......600*29.....724........488............*...............149*227.........*..................
+........@......278*............@..135..........594.........470*...........*....540*.......42..............................775.536..790......
+.....990...........742......181....*..............*..@521................743.......552............310...*....+738.....................*.....
+.......................125.......311............715........263...........................................173...................235....291...
--- a/03/input2.txt
+++ b/03/input2.txt
@@ -0,0 +1,3 @@
+.854...........................................................................362...........271...732........838.........24................
+...*.............................117*...........459........767*648....#.........*...................................$...&..=................
+....970.........368.124.+............57................653...........723.....366....*443..60.........536....441....45..879.....789...*......
--- a/03/input3.txt
+++ b/03/input3.txt
@@ -0,0 +1,10 @@
+467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...$.*....
+.664.598..