package main import ( "flag" "fmt" "strings" "github.com/alexchao26/advent-of-code-go/cast" "github.com/alexchao26/advent-of-code-go/mathy" "github.com/alexchao26/advent-of-code-go/util" ) func main() { var part int flag.IntVar(&part, "part", 1, "part 1 or 2") flag.Parse() fmt.Println("Running part", part) if part == 1 { ans := part1(util.ReadFile("./input.txt")) fmt.Println("Output:", ans) } else { ans := part2(util.ReadFile("./input.txt")) fmt.Println("Output:", ans) } } func part1(input string) int { rows := parseInput(input) var checksum int for _, r := range rows { checksum += mathy.MaxInt(r...) - mathy.MinInt(r...) } return checksum } func part2(input string) int { rows := parseInput(input) var sumDivisible int for _, r := range rows { for i, val1 := range r { for _, val2 := range r[i+1:] { if val1%val2 == 0 { sumDivisible += val1 / val2 break } else if val2%val1 == 0 { sumDivisible += val2 / val1 break } } } } return sumDivisible } func parseInput(input string) (ans [][]int) { lines := strings.Split(input, "\n") for i, l := range lines { ans = append(ans, []int{}) // split by tabs for _, num := range strings.Split(l, "\t") { ans[i] = append(ans[i], cast.ToInt(num)) } } return ans }