66 lines
1 KiB
Go
66 lines
1 KiB
Go
|
package d12
|
||
|
|
|
||
|
|
import (
|
||
|
|
"strings"
|
||
|
|
)
|
||
|
|
|
||
|
|
type caveMap map[string][]string
|
||
|
|
|
||
|
|
func getLines(in string) []string {
|
||
|
|
return strings.Split(strings.TrimSpace(in), "\n")
|
||
|
|
}
|
||
|
|
|
||
|
|
func getPairs(lines []string) [][]string {
|
||
|
|
pairs := [][]string{}
|
||
|
|
|
||
|
|
for _, line := range lines {
|
||
|
|
pairs = append(pairs, strings.Split(line, "-"))
|
||
|
|
}
|
||
|
|
|
||
|
|
return pairs
|
||
|
|
}
|
||
|
|
|
||
|
|
func createMap(paths [][]string) caveMap {
|
||
|
|
caveMap := make(map[string][]string)
|
||
|
|
|
||
|
|
for _, path := range paths {
|
||
|
|
left := path[0]
|
||
|
|
right := path[1]
|
||
|
|
|
||
|
|
caveMap[left] = append(caveMap[left], right)
|
||
|
|
caveMap[right] = append(caveMap[right], left)
|
||
|
|
}
|
||
|
|
|
||
|
|
return caveMap
|
||
|
|
}
|
||
|
|
|
||
|
|
func countPaths(caveMap caveMap, key string, visited map[string]int, duplicate bool) int {
|
||
|
|
count := 0
|
||
|
|
|
||
|
|
if key == "end" {
|
||
|
|
return 1
|
||
|
|
}
|
||
|
|
|
||
|
|
if visited[key] > 0 {
|
||
|
|
if key == "start" {
|
||
|
|
return 0
|
||
|
|
}
|
||
|
|
|
||
|
|
if strings.ToUpper(key) != key {
|
||
|
|
if duplicate {
|
||
|
|
return 0
|
||
|
|
} else {
|
||
|
|
duplicate = true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
visited[key]++
|
||
|
|
for _, path := range caveMap[key] {
|
||
|
|
count += countPaths(caveMap, path, visited, duplicate)
|
||
|
|
}
|
||
|
|
visited[key]--
|
||
|
|
|
||
|
|
return count
|
||
|
|
}
|