mirror of
https://github.com/Threnklyn/advent-of-code-go.git
synced 2026-05-18 19:13:27 +02:00
alexchao26
103 lines
2.5 KiB
Go
103 lines
2.5 KiB
Go
package main
|
|
|
|
import (
|
|
"github.com/alexchao26/advent-of-code-go/util"
|
|
"fmt"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
// Moon stores coordinates and velocities of a moon
|
|
type Moon struct {
|
|
x, y, z, dx, dy, dz int
|
|
}
|
|
|
|
func main() {
|
|
input := util.ReadFile("../input.txt")
|
|
stringSlice := strings.Split(input, "\n")
|
|
|
|
// need to set x y z, dx, dy, dz of each of the starting moons
|
|
sliceMoons := makeMoonSlice(stringSlice)
|
|
|
|
// iterate through for each step
|
|
for i := 0; i < 1000; i++ {
|
|
// iterate through all the moons in the slice
|
|
for start := 0; start < len(sliceMoons); start++ {
|
|
// update velocities dx dy dz
|
|
// requires iterating through all of the moons again...
|
|
for restIndex := start + 1; restIndex < len(sliceMoons); restIndex++ {
|
|
if sliceMoons[start].x < sliceMoons[restIndex].x {
|
|
sliceMoons[start].dx++
|
|
sliceMoons[restIndex].dx--
|
|
} else if sliceMoons[start].x > sliceMoons[restIndex].x {
|
|
sliceMoons[start].dx--
|
|
sliceMoons[restIndex].dx++
|
|
}
|
|
if sliceMoons[start].y < sliceMoons[restIndex].y {
|
|
sliceMoons[start].dy++
|
|
sliceMoons[restIndex].dy--
|
|
} else if sliceMoons[start].y > sliceMoons[restIndex].y {
|
|
sliceMoons[start].dy--
|
|
sliceMoons[restIndex].dy++
|
|
}
|
|
if sliceMoons[start].z < sliceMoons[restIndex].z {
|
|
sliceMoons[start].dz++
|
|
sliceMoons[restIndex].dz--
|
|
} else if sliceMoons[start].z > sliceMoons[restIndex].z {
|
|
sliceMoons[start].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
|
|
}
|
|
}
|
|
|
|
// get final kinetic energy
|
|
fmt.Println(kinetic(sliceMoons))
|
|
}
|
|
|
|
func makeMoonSlice(stringSlice []string) []Moon {
|
|
sliceMoons := make([]Moon, 0)
|
|
for _, str := range stringSlice {
|
|
xStart := strings.Index(str, "x=") + 2
|
|
xEnd := strings.Index(str, ",")
|
|
yStart := xEnd + 4
|
|
zStart := strings.Index(str, "z=") + 2
|
|
yEnd := zStart - 4
|
|
zEnd := len(str) - 1
|
|
|
|
x := str[xStart:xEnd]
|
|
y := str[yStart:yEnd]
|
|
z := str[zStart:zEnd]
|
|
|
|
intX, _ := strconv.Atoi(x)
|
|
intY, _ := strconv.Atoi(y)
|
|
intZ, _ := strconv.Atoi(z)
|
|
sliceMoons = append(sliceMoons, Moon{intX, intY, intZ, 0, 0, 0})
|
|
}
|
|
return sliceMoons
|
|
}
|
|
|
|
// get total "kinetic energy" of a slice of Moons
|
|
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 {
|
|
if value < 0 {
|
|
return value * -1
|
|
}
|
|
return value
|
|
}
|