act/pkg/common/cartesian.go

55 lines
1.0 KiB
Go

package common
// CartesianProduct takes map of lists and returns list of unique tuples
func CartesianProduct(mapOfLists map[string][]interface{}) []map[string]interface{} {
listNames := make([]string, 0)
lists := make([][]interface{}, 0)
for k, v := range mapOfLists {
listNames = append(listNames, k)
lists = append(lists, v)
}
listCart := cartN(lists...)
rtn := make([]map[string]interface{}, 0)
for _, list := range listCart {
vMap := make(map[string]interface{})
for i, v := range list {
vMap[listNames[i]] = v
}
rtn = append(rtn, vMap)
}
return rtn
}
func cartN(a ...[]interface{}) [][]interface{} {
c := 1
for _, a := range a {
c *= len(a)
}
if c == 0 || len(a) == 0 {
return nil
}
p := make([][]interface{}, c)
b := make([]interface{}, c*len(a))
n := make([]int, len(a))
s := 0
for i := range p {
e := s + len(a)
pi := b[s:e]
p[i] = pi
s = e
for j, n := range n {
pi[j] = a[j][n]
}
for j := len(n) - 1; j >= 0; j-- {
n[j]++
if n[j] < len(a[j]) {
break
}
n[j] = 0
}
}
return p
}