days 1 and 2

.gitignore

@@ -0,0 +1,2 @@
+bin
+input

day1/Makefile

@@ -0,0 +1,8 @@
+part1: part1.c
+	gcc -Wall -g -o bin/part1 part1.c 
+part2: part2.c
+	gcc -Wall -g -o bin/part2 part2.c
+
+.PHONY: clean
+clean:
+	rm part1 part2

day1/part1.c

@@ -0,0 +1,78 @@
+#include <ctype.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+/*
+ * Each line of the input file contains a string with a mix of letters and digits
+ * Each line's "calibration value" is a single two digit number, made up of the first and last
+ * digit found in the string
+ * Print out the sum of all the calibration values. 
+ */
+
+char buffer[2048];
+
+void read_line(char* linebuf, FILE* file) 
+{
+    char* str = fgets(linebuf, 2048, file);
+    if (feof(file))
+    {
+        return;
+    }
+    if (str == NULL)
+    {
+        fprintf(stderr, "Fgets error");
+        linebuf[0] = '\0';
+    }
+}
+
+void extract_digits(char* str, char *first, char *last)
+{
+    char *p,*q,*r;
+    p = str;
+    while (*p != '\0' && !isdigit(*p))
+        p++; // find first digit
+    *first = *last = *p;
+    q = p;
+    while (*q != '\0') // find digits until end of string
+    {
+        q++;
+        if (isdigit(*q))
+        {
+            *last = *q;
+        }
+    }
+}
+
+long convert_chars(char first, char last)
+{
+    char num[3] = { first, last, '\0' };
+    return strtoul(num, NULL, 10);
+}
+
+int main(int argc, char *argv[])
+{
+    FILE* input = fopen("input", "r"); 
+    if (input == NULL)
+    {
+        fprintf(stderr, "error opening file");
+        return EXIT_FAILURE;
+    }
+    long sum = 0;
+    char first, last;
+    
+    while(true)
+    {
+        read_line(buffer, input);
+        if (feof(input))
+            break;
+        extract_digits(buffer, &first, &last);
+        long value = convert_chars(first, last);
+        printf("%ld\t%s", value, buffer);
+        sum += value;
+    }
+
+    printf("%ld", sum);
+    return EXIT_SUCCESS;
+}

day1/part2.c

@@ -0,0 +1,136 @@
+#include <ctype.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+/*
+ * Each line of the input file contains a string with a mix of letters and digits
+ * Each line's "calibration value" is a single two digit number, made up of the first and last
+ * digit found in the string
+ * Print out the sum of all the calibration values. 
+ */
+
+char buffer[2048];
+
+void read_line(char* linebuf, FILE* file) 
+{
+    char* str = fgets(linebuf, 2048, file);
+    if (feof(file))
+    {
+        return;
+    }
+    if (str == NULL)
+    {
+        fprintf(stderr, "Fgets error");
+        linebuf[0] = '\0';
+    }
+}
+
+bool parse_digit(const char* str, char* result, int* n)
+{
+    char* nums[] = {"one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};
+    int numslen[] = {3, 3, 5, 4, 4, 3, 5, 5, 4};
+    char numschar[] = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};
+    for (int i = 0; i < 9; i++)
+    {
+        if(strncmp(str, nums[i], numslen[i]) == 0)
+        {
+            *result = numschar[i];
+            *n = numslen[i];
+            return true;
+        }
+    }
+    return false;
+}
+
+void extract_digits(char* str, char *first, char *last)
+{
+    char *p,*q;
+    p = str;
+    int n;
+    bool found = false;
+    while (*p != '\0' && !found)
+    {
+        switch(*p)
+        {
+            case 'o':
+            case 't':
+            case 'f':
+            case 's':
+            case 'e':
+            case 'n':
+                if(parse_digit(p, first, &n))
+                {
+                    found = true;
+                    break;
+                }
+            default:
+                if (isdigit(*p))
+                {
+                    *first = *p;
+                    found = true;
+                }
+                else
+                    p++;
+        }
+    }
+    q = p;
+    *last = *first;
+    while (*q != '\0') // find next digit
+    {
+        switch(*q)
+        {
+            case 'o':
+            case 't':
+            case 'f':
+            case 's':
+            case 'e':
+            case 'n':
+                if(parse_digit(q, last, &n))
+                {
+                    q++;
+                    break;
+                }
+            default:
+                if (isdigit(*q))
+                {
+                    *last = *q;
+                }
+                q++;
+        }
+    }
+}
+
+long convert_chars(char first, char last)
+{
+    char num[3] = { first, last, '\0' };
+    return strtoul(num, NULL, 10);
+}
+
+int main(int argc, char *argv[])
+{
+    FILE* input = fopen("input", "r"); 
+    if (input == NULL)
+    {
+        fprintf(stderr, "error opening file");
+        return EXIT_FAILURE;
+    }
+    long sum = 0;
+    char first, last;
+    
+    while(true)
+    {
+        read_line(buffer, input);
+        if (feof(input))
+            break;
+        extract_digits(buffer, &first, &last);
+        long value = convert_chars(first, last);
+        printf("%ld\t%c\t%c\t%s", value, first, last, buffer);
+        sum += value;
+    }
+
+    printf("%ld", sum);
+    return EXIT_SUCCESS;
+}

day2/Makefile

@@ -0,0 +1,8 @@
+part1: part1.c
+	gcc -Wall -g -o bin/part1 part1.c 
+part2: part2.c
+	gcc -Wall -g -o bin/part2 part2.c
+
+.PHONY: clean
+clean:
+	rm part1 part2

day2/part1.c

@@ -0,0 +1,215 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <regex.h>
+#include <string.h>
+
+typedef struct elfgame {
+    long number; 
+    struct elfgame_play *plays;
+    struct elfgame *next;
+} elfgame;
+
+typedef struct elfgame_play {
+    long red, blue, green;
+    struct elfgame_play *next;
+} elfgame_play;
+
+elfgame *first_game;
+
+void read_line(char* linebuf, FILE* file) 
+{
+    char* str = fgets(linebuf, 2048, file);
+    if (feof(file))
+    {
+        return;
+    }
+    if (str == NULL)
+    {
+        fprintf(stderr, "Fgets error");
+        linebuf[0] = '\0';
+    }
+}
+
+long get_gamenum(char* line)
+{
+    regex_t regex;
+    char pattern[] = "Game ([0-9]+):.*";
+    regmatch_t pmatch[2];
+    if (regcomp(&regex, pattern, REG_EXTENDED))
+    {
+        fprintf(stderr, "error compiling regex");
+        return -1;
+    }
+    int rc = regexec(&regex, line, 2, pmatch, 0);
+    if (rc)
+    {
+        char buf[2048];
+        regerror(rc, &regex, buf, 2048);
+        fprintf(stderr, "error execing regex");
+        return -1;
+    }
+    return strtoul(line + pmatch[1].rm_so, NULL, 10);
+}
+
+elfgame_play *parse_play(char *line, int offset)
+{
+    regex_t regex;
+    regmatch_t pmatch[3];
+    char pattern[] =  "([0-9]+)[[:space:]](red|green|blue);?";
+    char *s = line;
+    elfgame_play *p = malloc(sizeof(elfgame_play));
+    if (p == NULL)
+    {
+        fprintf(stderr, "OOM");
+        return NULL;
+    }
+    p->red = p->blue = p->green = 0;
+    if (regcomp(&regex, pattern, REG_EXTENDED))
+    {
+        fprintf(stderr, "error compiling regex");
+        return NULL;
+    }
+    for (int i = 0; ; i++)
+    {
+        if (regexec(&regex, s, 3, pmatch, 0))
+            break;
+        if (s >= line + offset)
+            break;
+        long count = strtoul(s + pmatch[1].rm_so, NULL, 10);
+        if (strncmp(s + pmatch[2].rm_so, "red", 3) == 0)
+        {
+            p->red += count;
+        }
+        if (strncmp(s + pmatch[2].rm_so, "blue", 4) == 0)
+        {
+            p->blue += count;
+        }
+        if (strncmp(s + pmatch[2].rm_so, "green", 5) == 0)
+        {
+            p->green += count;
+        }
+        s += pmatch[0].rm_eo;
+    }
+    regfree(&regex);
+    return p;
+}
+
+elfgame_play *parse_plays(char* line, int offset)
+{
+    regex_t regex;
+    regmatch_t pmatch[3];
+    char pattern[] =  "([0-9]+)[[:space:]](red|blue|green)";
+    char *s = line;
+    elfgame_play *first = malloc(sizeof(elfgame_play));
+    if (first == NULL)
+    {
+        fprintf(stderr, "OOM");
+        return NULL;
+    }
+    elfgame_play *cur = first;
+    if (regcomp(&regex, pattern, REG_EXTENDED))
+    {
+        fprintf(stderr, "error compiling regex");
+        return NULL;
+    }
+    for (int i = 0; ; i++)
+    {
+        if (regexec(&regex, s, 3, pmatch, 0))
+            break;
+        if (s > line + offset)
+            break;
+        elfgame_play *p = malloc(sizeof(elfgame_play));
+        if (p == NULL)
+        {
+            fprintf(stderr, "OOM");
+            return NULL;
+        }
+        p->red = p->blue = p->green = 0;
+        long count = strtoul(s + pmatch[1].rm_so, NULL, 10);
+        if (strncmp(s + pmatch[2].rm_so, "red", 3) == 0)
+        {
+            p->red += count;
+        }
+        if (strncmp(s + pmatch[2].rm_so, "blue", 4) == 0)
+        {
+            p->blue += count;
+        }
+        if (strncmp(s + pmatch[2].rm_so, "green", 5) == 0)
+        {
+            p->green += count;
+        }
+        cur->next = p;
+        cur = cur->next;
+        s += pmatch[0].rm_eo;
+    }
+    return first; 
+}
+
+elfgame *parse_game(char* line)
+{
+    regex_t regex;
+    regmatch_t pmatch[4];
+    char pattern[] = "(([0-9]+)[[:space:]](red|blue|green),?[[:space:]]?)+;?";
+    if (regcomp(&regex, pattern, REG_EXTENDED))
+    {
+        fprintf(stderr, "error compiling regex");
+        return NULL;
+    }
+    char *s = line;
+    elfgame *g = malloc(sizeof(elfgame));
+    if (g == NULL)
+    {
+        return NULL;
+    }
+    g->number = get_gamenum(line); 
+    elfgame_play *dummy = malloc(sizeof(elfgame_play));
+    if (dummy == NULL)
+    {
+        return NULL;
+    }
+    dummy->red = dummy->green = dummy->blue = 0;
+    elfgame_play *cur = dummy;
+    g->plays = dummy;
+    for (int i = 0; ; i++)
+    {
+        if(regexec(&regex, s, 4, pmatch, 0))
+            break;
+        cur->next = parse_play(line, pmatch[0].rm_eo);
+        cur = cur->next;
+        s += pmatch[0].rm_eo;
+    }
+    regfree(&regex);
+    return g;
+}
+
+int main(int argc, char *argv[])
+{
+    char buffer[2048];
+    FILE* input = fopen("input", "r"); 
+    if (input == NULL)
+    {
+        fprintf(stderr, "error opening file");
+        return EXIT_FAILURE;
+    }
+    long sum = 0;
+    first_game = malloc(sizeof(elfgame));
+    if (first_game == NULL)
+    {
+        fprintf(stderr, "OOM");
+        return EXIT_FAILURE;
+    }
+    elfgame *cur = first_game;
+    while(true)
+    {
+        read_line(buffer, input);
+        if (feof(input))
+            break;
+        elfgame *g = parse_game(buffer);
+        cur->next = g;
+        cur = cur->next;
+    }
+
+    printf("%ld", sum);
+    return EXIT_SUCCESS;
+}

day2/part1.py

@@ -0,0 +1,63 @@
+import re
+
+
+class Game:
+    def __init__(self, id, r=0, b=0, g=0):
+        self.id = id
+        self.red = r
+        self.blue = b
+        self.green = g
+
+    def __str__(self):
+        return f'game: {self.id}, max_red={self.red}, max_blue={self.blue}, max_green={self.green}'
+
+
+game_pattern = re.compile(r'Game ([0-9]+):\s(.*)')
+play_pattern = re.compile(r'([0-9]+)\s(red|green|blue)')
+total_red = 12
+total_blue = 14
+total_green = 13
+
+
+def parse_game(line):
+    m = game_pattern.search(line)
+    plays = m.groups()[1].split('; ')
+    game = Game(int(m.groups()[0]))
+    for play in plays:
+        counts = play.split(', ')
+        for c in counts:
+            r = b = g = 0
+            pm = play_pattern.search(c)
+            if pm.groups()[1] == 'red':
+                r = int(pm.groups()[0])
+            if pm.groups()[1] == 'blue':
+                b = int(pm.groups()[0])
+            if pm.groups()[1] == 'green':
+                g = int(pm.groups()[0])
+             
+            game.red = max(game.red, r)
+            game.blue = max(game.blue, b)
+            game.green = max(game.green, g)
+    return game
+
+
+def main():
+    games = []
+    with open('input', 'r') as f:
+        while True:
+            line = f.readline()
+            if not line:
+                break
+            games.append(parse_game(line))
+
+    sum = 0
+    for g in games:
+        if g.red > total_red or g.blue > total_blue or g.green > total_green:
+            continue
+        sum += g.id
+    print(sum)
+
+
+
+if __name__ == '__main__':
+    main()

day2/part2.py

@@ -0,0 +1,62 @@
+import re
+
+
+class Game:
+    def __init__(self, id, r=0, b=0, g=0):
+        self.id = id
+        self.red = r
+        self.blue = b
+        self.green = g
+
+    def __str__(self):
+        return f'game: {self.id}, max_red={self.red}, max_blue={self.blue}, max_green={self.green}'
+
+
+game_pattern = re.compile(r'Game ([0-9]+):\s(.*)')
+play_pattern = re.compile(r'([0-9]+)\s(red|green|blue)')
+total_red = 12
+total_blue = 14
+total_green = 13
+
+
+def parse_game(line):
+    m = game_pattern.search(line)
+    plays = m.groups()[1].split('; ')
+    game = Game(int(m.groups()[0]))
+    for play in plays:
+        counts = play.split(', ')
+        for c in counts:
+            r = b = g = 0
+            pm = play_pattern.search(c)
+            if pm.groups()[1] == 'red':
+                r = int(pm.groups()[0])
+            if pm.groups()[1] == 'blue':
+                b = int(pm.groups()[0])
+            if pm.groups()[1] == 'green':
+                g = int(pm.groups()[0])
+             
+            game.red = max(game.red, r)
+            game.blue = max(game.blue, b)
+            game.green = max(game.green, g)
+    return game
+
+
+def main():
+    games = []
+    with open('input', 'r') as f:
+        while True:
+            line = f.readline()
+            if not line:
+                break
+            games.append(parse_game(line))
+
+    sum = 0
+    for g in games:
+        power = g.red * g.blue * g.green
+        sum += power
+    print(sum)
+
+
+
+if __name__ == '__main__':
+    main()