day 12 part 1, part2 is wild

day12/part1/main.go

@@ -0,0 +1,116 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"math"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+type moon struct {
+	x, y, z, dx, dy, dz int
+}
+
+func main() {
+	stringSlice := readInputFile("../input.txt")
+	// fmt.Println(stringSlice)
+
+	// need to set x y z, dx, dy, dz of each of the starting moons
+	sliceMoons := make([]moon, 0)
+	for _, str := range stringSlice {
+		x := str[strings.Index(str, "x=")+2 : strings.Index(str, ",")]
+		// this is gross
+		y := str[strings.Index(str, "y=")+2 : strings.Index(str, "y=")+strings.Index(str[strings.Index(str, ",")+1:], ",")-1]
+		z := str[strings.Index(str, "z=")+2 : len(str)-1]
+
+		intx, _ := strconv.Atoi(x)
+		inty, _ := strconv.Atoi(y)
+		intz, _ := strconv.Atoi(z)
+		sliceMoons = append(sliceMoons, moon{intx, inty, intz, 0, 0, 0})
+	}
+	// fmt.Println(sliceMoons)
+
+	// iterate through for each step
+	for i := 0; i < 1000; i++ {
+		// iterate through all the moons in the slice
+		for index, element := range sliceMoons {
+			// update velocities dx dy dz
+			// requires iterating through all of the moons again...
+			for restIndex := index + 1; restIndex < len(sliceMoons); restIndex++ {
+				if element.x < sliceMoons[restIndex].x {
+					sliceMoons[index].dx++
+					sliceMoons[restIndex].dx--
+				} else if element.x > sliceMoons[restIndex].x {
+					sliceMoons[index].dx--
+					sliceMoons[restIndex].dx++
+				}
+				if element.y < sliceMoons[restIndex].y {
+					sliceMoons[index].dy++
+					sliceMoons[restIndex].dy--
+				} else if element.y > sliceMoons[restIndex].y {
+					sliceMoons[index].dy--
+					sliceMoons[restIndex].dy++
+				}
+				if element.z < sliceMoons[restIndex].z {
+					sliceMoons[index].dz++
+					sliceMoons[restIndex].dz--
+				} else if element.z > sliceMoons[restIndex].z {
+					sliceMoons[index].dz--
+					sliceMoons[restIndex].dz++
+				}
+
+			}
+
+			// then update coordinates x y z
+		}
+		for i2, e := range sliceMoons {
+			sliceMoons[i2].x += e.dx
+			sliceMoons[i2].y += e.dy
+			sliceMoons[i2].z += e.dz
+		}
+		// fmt.Println(sliceMoons)
+	}
+
+	// get final kinetic energy?
+	fmt.Println(kinetic(sliceMoons))
+}
+
+func kinetic(moons []moon) (result int) {
+	for _, e := range moons {
+		sumXYZ := abs(e.x) + abs(e.y) + abs(e.z)
+		velXYZ := abs(e.dx) + abs(e.dy) + abs(e.dz)
+		result += (sumXYZ * velXYZ)
+	}
+	return result
+}
+
+func abs(value int) int {
+	flt := float64(value)
+	return int(math.Abs(flt))
+}
+
+func readInputFile(path string) []string {
+	// var pixelString string
+	pixelSlice := make([]string, 0)
+	absPath, _ := filepath.Abs(path)
+
+	file, err := os.Open(absPath)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		// pixelString = line
+		pixelSlice = append(pixelSlice, line)
+	}
+
+	// return pixelString
+	return pixelSlice
+}