I was wondering if there was a way to find all the permutations of an slice filled with characters in Go?
In Python you can use itertools.product
with a list or characters or integers, and you can get all the possible permutations.
I have looked to see if there is a package out there, and I cannot seem to find one. Any help would be welcomed.
Permutations of anything implementing sort.Interface
: Permutation{First,Next}
Here is a implementation of a permutation function i've written...
https://github.com/itcraftsman/GoPermutation
func permutate(slice [][]int) (permutations [][][]int){
f := fac(len(slice))
for i := 0; i < len(slice); i++ {
elem, s := splice(slice, i)
pos := 0
for count := 0; count < (f / len(slice)); count++{
if pos == (len(s) -1) {
pos = 0
}
s = swap(s, pos, pos +1)
permutation := make([][]int, len(slice))
permutation = s
permutation = append(permutation, elem)
permutations = append(permutations, permutation)
pos++
}
}
return
}
it takes a 2D slice as input and returns a 3D slice, but you can easily change the code so that the function will take a simple slice as input and return a 2D slice with all permutations
Not really sure if this answers your question but this is a simple recursive implementation to find the output below.
package main
import "fmt"
func main() {
values := [][]int{}
// These are the first two rows.
row1 := []int{1, 2, 3}
row2 := []int{4, 5, 6}
row3 := []int{7, 8, 9}
// Append each row to the two-dimensional slice.
values = append(values, row1)
values = append(values, row2)
values = append(values, row3)
fmt.Println(getPermutation(values))
}
func getPermutation(vids [][]int) [][]int {
toRet := [][]int{}
if len(vids) == 0 {
return toRet
}
if len(vids) == 1 {
for _, vid := range vids[0] {
toRet = append(toRet, []int{vid})
}
return toRet
}
t := getPermutation(vids[1:])
for _, vid := range vids[0] {
for _, perm := range t {
toRetAdd := append([]int{vid}, perm...)
toRet = append(toRet, toRetAdd)
}
}
return toRet
}
https://play.golang.org/p/f8wktrxkU0
Output of above snippet:
[[1 4 7] [1 4 8] [1 4 9] [1 5 7] [1 5 8] [1 5 9] [1 6 7] [1 6 8] [1 6 9] [2 4 7] [2 4 8] [2 4 9] [2 5 7] [2 5 8] [2 5 9] [2 6 7] [2 6 8] [2 6 9] [3 4 7] [3 4 8] [3 4 9] [3 5 7] [3 5 8] [3 5 9] [3 6 7] [3 6 8] [3 6 9]]