✨Added Day 2 Solution

Day 2/README.md

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+# Day 2: Dive!
+
+Now, you need to figure out how to pilot this thing.
+
+It seems like the submarine can take a series of commands like `forward 1`, `down 2`, or `up 3`:
+
+- `forward X` increases the horizontal position by `X` units.
+- `down X` **increases** the depth by `X` units.
+- `up X` **decreases** the depth by `X` units.
+
+Note that since you're on a submarine, `down` and `up` affect your **depth**, and so they have the opposite result of what you might expect.
+
+The submarine seems to already have a planned course (your puzzle input). You should probably figure out where it's going. For example:
+
+```
+forward 5
+down 5
+forward 8
+up 3
+down 8
+forward 2
+```
+
+Your horizontal position and depth both start at 0. The steps above would then modify them as follows:
+
+- `forward 5` adds `5` to your horizontal position, a total of `5`.
+- `down 5` adds `5` to your depth, resulting in a value of `5`.
+- `forward 8` adds `8` to your horizontal position, a total of `13`.
+- `up 3` decreases your depth by `3`, resulting in a value of `2`.
+- `down 8` adds `8` to your depth, resulting in a value of `10`.
+- `forward 2` adds `2` to your horizontal position, a total of `15`.
+
+After following these instructions, you would have a horizontal position of `15` and a depth of `10`. (Multiplying these together produces `150`.)
+
+Calculate the horizontal position and depth you would have after following the planned course. **What do you get if you multiply your final horizontal position by your final depth?**
+
+# Part Two
+
+Based on your calculations, the planned course doesn't seem to make any sense. You find the submarine manual and discover that the process is actually slightly more complicated.
+
+In addition to horizontal position and depth, you'll also need to track a third value, **aim**, which also starts at `0`. The commands also mean something entirely different than you first thought:
+
+- `down X` **increases** your aim by `X` units.
+- `up X` **decreases** your aim by `X` units.
+- `forward X` does two things:
+  - It increases your horizontal position by `X` units.
+  - It increases your depth by your aim **multiplied by** `X`.
+
+Again note that since you're on a submarine, `down` and `up` do the opposite of what you might expect: "down" means aiming in the positive direction.
+
+Now, the above example does something different:
+
+- `forward 5` adds `5` to your horizontal position, a total of `5`. Because your aim is `0`, your depth does not change.
+- `down 5` adds `5` to your aim, resulting in a value of `5`.
+- `forward 8` adds `8` to your horizontal position, a total of `13`. Because your aim is `5`, your depth increases by `8*5=40`.
+- `up 3` decreases your aim by `3`, resulting in a value of `2`.
+- `down 8` adds `8` to your aim, resulting in a value of `10`.
+- `forward 2` adds `2` to your horizontal position, a total of `15`. Because your aim is `10`, your depth increases by `2*10=20` to a total of `60`.
+
+After following these new instructions, you would have a horizontal position of `15` and a depth of `60`. (Multiplying these produces `900`.)
+
+Using this new interpretation of the commands, calculate the horizontal position and depth you would have after following the planned course. **What do you get if you multiply your final horizontal position by your final depth?**

Day 2/main.go

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+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+type Direction string
+
+const(
+	Forward Direction = "forward"
+	Up = "up"
+	Down = "down"
+)
+
+type Command struct {
+	direction Direction
+	amount int
+}
+
+func partOne(commands []Command) {
+	horiPos := 0
+	depPos := 0
+	for _, command := range commands { 
+		switch command.direction {
+			case Forward:
+				horiPos += command.amount
+
+			case Up:
+				depPos -= command.amount
+
+			case Down:
+				depPos += command.amount
+		}
+	}
+
+	fmt.Printf("Part One Answer: %d\n", horiPos * depPos)
+}
+
+func partTwo(commands []Command) {
+	horiPos := 0
+	depPos := 0
+	aimPos := 0
+	for _, command := range commands { 
+		switch command.direction {
+			case Forward:
+				horiPos += command.amount
+				depPos += aimPos * command.amount
+
+			case Up:
+				aimPos -= command.amount
+
+			case Down:
+				aimPos += command.amount
+		}
+	}
+
+	fmt.Printf("Part Two Answer: %d\n", horiPos * depPos)
+}
+
+func main() {
+	file, err := os.Open("./input")
+	if err != nil {
+		fmt.Printf("[Error] Unable to open file")
+		os.Exit(1)
+	}
+	defer file.Close()
+
+	commands := []Command {}
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		command := strings.Split(scanner.Text(), " ")
+		if len(command) != 2 {
+			fmt.Printf("[Error] Invalid command parsed")
+			continue
+		}
+
+		amount, err := strconv.Atoi(command[1])
+		if err != nil {
+			fmt.Printf("[Error] Invalid amount parsed")
+			continue
+		}
+
+		switch command[0] {
+			case "forward":
+				commands = append(commands, Command{Forward,amount})
+
+			case "up":
+				commands = append(commands, Command{Up,amount})
+
+			case "down":
+				commands = append(commands, Command{Down,amount})
+
+			default:
+				fmt.Printf("[Error] Invalid command parsed")
+				continue
+		}
+	}
+
+	partOne(commands)
+	partTwo(commands)
+}