83 lines
1.3 KiB
Go
83 lines
1.3 KiB
Go
// This works fine for 12.1, but it's way too slow for 12.2
|
|
package day12
|
|
|
|
type Rule struct {
|
|
Positions [5]bool
|
|
Result bool
|
|
}
|
|
|
|
func (r Rule) String() string {
|
|
res := ""
|
|
for _, p := range r.Positions {
|
|
res += plantString(p)
|
|
}
|
|
res += " => "
|
|
res += plantString(r.Result)
|
|
return res
|
|
}
|
|
|
|
func plantString(isPlant bool) string {
|
|
if isPlant {
|
|
return "#"
|
|
}
|
|
return "."
|
|
}
|
|
|
|
func getPlantBounds(plants map[int]bool) (int, int) {
|
|
keys := make([]int, len(plants))
|
|
i := 0
|
|
for key, _ := range plants {
|
|
keys[i] = key
|
|
i++
|
|
}
|
|
|
|
low := keys[0]
|
|
high := keys[0]
|
|
for _, key := range keys {
|
|
if key < low {
|
|
low = key
|
|
}
|
|
if key > high {
|
|
high = key
|
|
}
|
|
}
|
|
|
|
return low, high
|
|
}
|
|
|
|
func RunGeneration(plants map[int]bool, rules []*Rule) map[int]bool {
|
|
newGen := make(map[int]bool)
|
|
|
|
low, high := getPlantBounds(plants)
|
|
|
|
for i := low - 2; i < high+3; i++ {
|
|
for _, rule := range rules {
|
|
if checkRule(plants, rule, i) {
|
|
newGen[i] = rule.Result
|
|
break // only one rule will match a given slice
|
|
}
|
|
}
|
|
}
|
|
|
|
return newGen
|
|
}
|
|
|
|
func checkRule(plants map[int]bool, rule *Rule, i int) bool {
|
|
for j := 0; j < 5; j++ {
|
|
if plants[i+j-2] != rule.Positions[j] {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func SumPlants(plants map[int]bool) int {
|
|
sum := 0
|
|
for key, value := range plants {
|
|
if value {
|
|
sum += key
|
|
}
|
|
}
|
|
return sum
|
|
}
|