82 lines
1.3 KiB
Go
82 lines
1.3 KiB
Go
package day12
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type Rule struct {
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Positions [5]bool
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Result bool
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}
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func (r Rule) String() string {
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res := ""
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for _, p := range r.Positions {
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res += plantString(p)
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}
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res += " => "
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res += plantString(r.Result)
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return res
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}
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func plantString(isPlant bool) string {
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if isPlant {
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return "#"
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}
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return "."
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}
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func getPlantBounds(plants map[int]bool) (int, int) {
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keys := make([]int, len(plants))
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i := 0
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for key, _ := range plants {
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keys[i] = key
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i++
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}
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low := keys[0]
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high := keys[0]
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for _, key := range keys {
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if key < low {
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low = key
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}
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if key > high {
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high = key
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}
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}
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return low, high
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}
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func RunGeneration(plants map[int]bool, rules []*Rule) map[int]bool {
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newGen := make(map[int]bool)
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low, high := getPlantBounds(plants)
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for i := low - 2; i < high+3; i++ {
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for _, rule := range rules {
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if checkRule(plants, rule, i) {
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newGen[i] = rule.Result
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break // only one rule will match a given slice
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}
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}
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}
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return newGen
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}
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func checkRule(plants map[int]bool, rule *Rule, i int) bool {
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for j := 0; j < 5; j++ {
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if plants[i+j-2] != rule.Positions[j] {
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return false
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}
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}
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return true
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}
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func SumPlants(plants map[int]bool) int {
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sum := 0
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for key, value := range plants {
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if value {
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sum += key
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}
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}
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return sum
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}
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