Committing days 1-4

02/02.c

@@ -0,0 +1,124 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#define STRBUF_SIZE 200
+
+enum color
+{
+    color_red = 0,
+    color_green,
+    color_blue
+};
+
+typedef struct gameresult_t
+{
+    uint8_t red;
+    uint8_t green;
+    uint8_t blue;
+} gameresult;
+
+gameresult parse_hand(char *str)
+{
+    gameresult result = {0};
+    uint8_t num = 0;
+
+    while (true)
+    {
+        num = 0;
+        while (*str != ' ')
+        {
+            num = (num * 10) + (*str - '0');
+            str++;
+        }
+
+        str++;
+
+        switch(*str)
+        {
+            case 'r':
+                result.red += num;
+                str += 3;
+                break;
+            case 'g':
+                result.green += num;
+                str += 5;
+                break;
+            case 'b':
+                result.blue += num;
+                str += 4;
+                break;
+        }
+
+        if (*str != ',') return result;
+
+        str += 2;
+    }
+}
+
+gameresult parse_game_maxes(char *str)
+{
+    // Keeps track of the most cubes of a single color seen any hand
+    gameresult maxes = {0};
+
+    // Keeps result from the most recent hand
+    gameresult result = {0};
+
+    while (*str != ':') str++;
+    
+    while (*str == ':' || *str == ';')
+    {
+        str += 2;
+        result = parse_hand(str);
+        if (result.red > maxes.red) maxes.red = result.red;
+        if (result.green > maxes.green) maxes.green = result.green;
+        if (result.blue > maxes.blue) maxes.blue = result.blue;
+        while (*str != ';' && *str != '\n') str++;
+    }
+
+    return maxes;
+}
+
+bool game_is_valid(char *str)
+{
+    gameresult maxes = {0};
+
+    maxes = parse_game_maxes(str);
+
+    return (maxes.red <= 12 && maxes.green <= 13 && maxes.blue <= 14);
+}
+
+int main(int argc, char **argv)
+{
+    // Get filename as an argument, defaults to "input.txt"
+    char *path = (argc > 1) ? argv[1] : "input.txt";
+
+    if (!path)
+    {
+        printf("Requires input file.\n");
+        return 1;
+    }
+
+    FILE *file = fopen(path, "r");
+
+    if (!file)
+    {
+        printf("Could not find file.");
+        return 1;
+    }
+
+    char strbuf[STRBUF_SIZE] = {0};
+    uint8_t gamenum = 1;
+    uint32_t sum = 0;
+
+    while (fgets(strbuf, 200, file))
+    {
+        if (game_is_valid(strbuf))
+            sum += gamenum;
+        gamenum++;
+    }
+
+    printf("Sum: %d\n", sum);
+
+    return 0;
+}