✨ Finish part 1 & part 2 of day 6

day6/main.go

@@ -0,0 +1,149 @@
+package main
+
+import (
+	"bufio"
+	"log"
+	"math"
+	"os"
+	"strconv"
+	"strings"
+)
+
+type (
+	Planet struct {
+		Name    string
+		Planets []*Planet
+		Orbit   []*Planet
+	}
+)
+
+func main() {
+	file, err := os.Open("input.txt")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	cmds := make([]string, 0)
+	for scanner.Scan() {
+		cmds = append(cmds, scanner.Text())
+	}
+
+	planets := ParseMap(cmds)
+
+	log.Println("Part1: " + strconv.Itoa(SolvePzl1(planets)))
+	log.Println("Part2: " + strconv.Itoa(SolvePzl2(planets)))
+}
+
+func SolvePzl1(planets []*Planet) int {
+	sum := 0
+	for i := 0; i < len(planets); i++ {
+		sum += CountOrbits(planets[i])
+	}
+	return sum
+}
+
+func SolvePzl2(planets []*Planet) int {
+	startPlanet := FindPlanet("YOU", planets)
+	sum, _ := CountPath("SAN", startPlanet, make([]*Planet, 0))
+	return sum - 2
+}
+
+func ParseMap(list []string) []*Planet {
+	planets := make([]*Planet, 0)
+	var orbitPlanet *Planet
+	var inPlanet *Planet
+
+	for _, cmd := range list {
+		parts := strings.Split(cmd, ")")
+		inPlanetName := parts[0]
+		orbitName := parts[1]
+
+		orbitPlanet, planets = GetOrInitialPlanet(orbitName, planets)
+		inPlanet, planets = GetOrInitialPlanet(inPlanetName, planets)
+
+		orbitPlanet.Planets = append(orbitPlanet.Planets, inPlanet)
+		inPlanet.Orbit = append(inPlanet.Orbit, orbitPlanet)
+	}
+	return planets
+}
+
+func CountOrbits(planet *Planet) int {
+	sum := len(planet.Planets)
+
+	if sum == 0 {
+		return 0
+	}
+
+	for i := 0; i < len(planet.Planets); i++ {
+		sum += CountOrbits(planet.Planets[i])
+	}
+	return sum
+}
+
+func CountPath(destination string, currentPlanet *Planet, checkedPlanets []*Planet) (int, bool) {
+
+	if currentPlanet.Name == destination {
+		return 0, true
+	}
+
+	if FindPlanet(currentPlanet.Name, checkedPlanets) != nil {
+		return -1, false
+	}
+
+	if len(currentPlanet.Planets) == 0 {
+		return -1, false
+	}
+	checkedPlanets = append(checkedPlanets, currentPlanet)
+
+	minimumCost := math.MaxInt32
+	wasSuccess := false
+
+	for i := 0; i < len(currentPlanet.Orbit); i++ {
+		path, success := CountPath(destination, currentPlanet.Orbit[i], checkedPlanets)
+		path += 1
+		if success {
+			wasSuccess = true
+			if path <= minimumCost {
+				minimumCost = path
+			}
+		}
+	}
+
+	for i := 0; i < len(currentPlanet.Planets); i++ {
+		path, success := CountPath(destination, currentPlanet.Planets[i], checkedPlanets)
+		path += 1
+		if success {
+			wasSuccess = true
+			if path <= minimumCost {
+				minimumCost = path
+			}
+		}
+	}
+
+	return minimumCost, wasSuccess
+}
+
+func FindPlanet(name string, planets []*Planet) *Planet {
+	for i := 0; i < len(planets); i++ {
+		if planets[i].Name == name {
+			return planets[i]
+		}
+	}
+	return nil
+}
+
+func GetOrInitialPlanet(name string, planets []*Planet) (*Planet, []*Planet) {
+	planet := FindPlanet(name, planets)
+
+	if planet == nil {
+		planet = &Planet{
+			Name:    name,
+			Planets: make([]*Planet, 0),
+			Orbit:   make([]*Planet, 0),
+		}
+		planets = append(planets, planet)
+	}
+	return planet, planets
+}