package main
import "fmt"
func main() {
aa := []string{"a", "b", "c", "d"}
fmt.Println(permutation(aa))
}
func permutation(sarr []string) (rets []string) {
if len(sarr) == 1 {
rets = sarr
return rets
}
for i := 0; i < len(sarr); i++ {
// append(sarr[:i], sarr[i+1:]...)直接append会改变sarr
sonsarr := permutation(append(append([]string{}, sarr[:i]...), sarr[i+1:]...))
for _, sons := range sonsarr {
rets = append(rets, sarr[i]+sons)
}
}
return rets
}