91 lines
1.7 KiB
Go
91 lines
1.7 KiB
Go
package main
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import (
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"fmt"
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"sort"
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helpers "git.bullercodeworks.com/brian/adventofcode/helpers"
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)
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const MaxInt = int(^uint(0) >> 1)
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var field []helpers.Coordinate
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func main() {
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inp := helpers.StdinToStringSlice()
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initField(inp)
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solve()
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}
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func initField(inp []string) {
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for y, yb := range inp {
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for x, xb := range yb {
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if xb != '#' {
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continue
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}
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field = append(field, helpers.Coordinate{X: x, Y: y})
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}
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}
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}
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func solve() {
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// Figure out the best place to put the station
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var bestCount int
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var best helpers.Coordinate
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var bestAngles map[float64][]helpers.Coordinate
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for _, wrk := range field {
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angles := make(map[float64][]helpers.Coordinate)
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var count int
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for _, tgt := range field {
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if wrk == tgt {
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continue
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}
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a := wrk.Angle(tgt)
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if _, ok := angles[a]; !ok {
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count++
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}
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angles[a] = append(angles[a], tgt)
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}
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if count > bestCount {
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bestCount = count
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best = wrk
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bestAngles = angles
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}
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}
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fmt.Println("Part 1:", best, bestCount)
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var angleSlice []float64
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for k := range bestAngles {
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angleSlice = append(angleSlice, k)
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}
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sort.Float64s(angleSlice)
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// Now start vaporizing
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var hitCount int
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var c200 helpers.Coordinate
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for k := range bestAngles {
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sort.Slice(bestAngles[k], func(i, j int) bool {
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return bestAngles[k][i].Distance(best) < bestAngles[k][j].Distance(best)
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})
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}
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for len(bestAngles) > 0 {
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for _, v := range angleSlice {
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if roids, ok := bestAngles[v]; ok {
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// Destroy the first asteroid in the list
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hitCount++
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if hitCount == 200 {
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c200 = roids[0]
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res := (c200.X*100 + c200.Y)
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fmt.Println("Part 2:", c200, res)
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return
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}
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if len(roids) > 1 {
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bestAngles[v] = roids[1:]
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} else {
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delete(bestAngles, v)
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}
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}
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}
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}
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}
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