day 2 done

day2/c/Makefile

@@ -0,0 +1,9 @@
+CC=gcc
+CFLAGS=-std=gnu99 -O2 -g
+PROJECT=aoc_day2
+
+%.o: %.c
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+$(PROJECT): aoc_day2.o
+	$(CC) -o aoc_day2 aoc_day2.o

day2/c/aoc_day2.c

@@ -0,0 +1,113 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define INPUT_FILE ("../input.txt")
+#define ARR_LEN (1000)
+
+typedef enum direction
+{
+	DIR_FORWARD = 0,
+	DIR_UP = 1,
+	DIR_DOWN = 2
+}direction;
+
+// this is just direction + amount
+typedef struct action_t
+{
+	direction dir;
+	int amount;
+}action_t;
+
+int main(int argc, char** argv)
+{
+	int horizontal_pos = 0;
+	int depth = 0;
+	int aim = 0;
+
+	FILE* fp = fopen(INPUT_FILE, "r");
+	if(fp == NULL)
+	{
+		printf("Failed to open file for reading...\n");
+		exit(-1);
+	}
+
+	size_t len = 0;
+	ssize_t rc = 0;
+	char* line = NULL;
+	char action[12];
+
+	action_t action_bank[ARR_LEN];
+	memset(action_bank, 0, sizeof(action_t) * ARR_LEN);
+	int ct = 0;
+	while((rc = getline(&line, &len, fp)) > 0)
+	{
+		memset(action, '\0', 12);
+		int amount = 0;
+		sscanf(line, "%s %d", action, &amount);
+		action_bank[ct].amount = amount;
+		if(strcmp(action, "forward") == 0)
+		{
+			action_bank[ct].dir = DIR_FORWARD;
+			horizontal_pos += amount;
+		}
+		else if(strcmp(action, "up") == 0)
+		{
+			action_bank[ct].dir = DIR_UP;
+			depth -= amount;
+		}
+		else if(strcmp(action, "down") == 0)
+		{
+			action_bank[ct].dir = DIR_DOWN;
+			depth += amount;
+		}
+		else
+		{
+			printf("action didn't match any known actions -- action: %s\n", action);
+			exit(-1);
+		}
+		ct++;
+	}
+	printf("Part 1\n");
+	printf("Horizontal Position: %d\n", horizontal_pos);
+	printf("Depth: %d\n", depth);
+	printf("calculated course: %d\n", depth * horizontal_pos);
+
+	// part 2
+	horizontal_pos = 0;
+	depth = 0;
+	for(int ind = 0; ind < ARR_LEN; ind++)
+	{
+		/* printf(">>>ACTION: %s\tAMOUNT: %d\n", */
+		/* 	   action_bank[ind].dir == DIR_FORWARD ? "FORWARD" : */
+		/* 	   action_bank[ind].dir == DIR_UP ? "UP" : */
+		/* 	   action_bank[ind].dir == DIR_DOWN ? "DOWN" : "UNKNOWN", */
+		/* 	   action_bank[ind].amount); */
+		if(action_bank[ind].dir == DIR_FORWARD)
+		{
+			horizontal_pos += action_bank[ind].amount;
+			depth += (aim * action_bank[ind].amount);
+		}
+		else if(action_bank[ind].dir == DIR_UP)
+		{
+			aim -= action_bank[ind].amount;
+		}
+		else if(action_bank[ind].dir == DIR_DOWN)
+		{
+			aim += action_bank[ind].amount;
+		}
+		else
+		{
+			printf("Error, dir unknown\n");
+			exit(-1);
+		}
+
+	}
+	printf("Part 2\n");
+	printf("Horizontal Position: %d\n"
+		   "Depth: %d\n"
+		   "Aim: %d\n", horizontal_pos, depth, aim);
+
+	printf("Final Position: %d\n", horizontal_pos * depth);
+	return 0;
+}