Advent of Code 2021 Day 2

2a.go

package main

import (
	_ "embed"
	"fmt"
	"strconv"
	"strings"
)

//go:embed input.txt
var input string

func main() {
	lines := strings.Split(input, "\n")
	horiz := 0
	vert := 0
	for _, line := range lines {
		vals := strings.Split(line, " ")
		num, err := strconv.Atoi(vals[1])
		if err != nil {
			panic(err)
		}
		switch vals[0] {
		case "forward":
			horiz += num
		case "down":
			vert += num
		case "up":
			vert -= num
		}
	}

	fmt.Println(horiz * vert)
}

2b.go

package main

import (
	_ "embed"
	"fmt"
	"strconv"
	"strings"
)

//go:embed input.txt
var input string

func main() {
	lines := strings.Split(input, "\n")
	aim := 0
	horiz := 0
	vert := 0
	for _, line := range lines {
		vals := strings.Split(line, " ")
		num, err := strconv.Atoi(vals[1])
		if err != nil {
			panic(err)
		}
		switch vals[0] {
		case "forward":
			horiz += num
			vert += num * aim
		case "down":
			aim += num
		case "up":
			aim -= num
		}
	}

	fmt.Println(horiz * vert)
}