Add digitPositions

numeral.go

@@ -38,6 +38,7 @@ import (
 type Numeral struct {
 	digits      *list.List
 	digitValues []rune
+	digitPositions map [rune]int
 }
 
 // NewNumeral initializes a numeral by providing the initial number in strings
@@ -47,6 +48,7 @@ func NewNumeral(values []rune, initial string) (*Numeral, error) {
 	number := Numeral{
 		digits:      list.New(),
 		digitValues: values,
+		digitPositions: valuesToPositions(values),
 	}
 	// add digits to the number along with their state.
 	for i := 0; i < len(initial); i++ {
@@ -59,6 +61,14 @@ func NewNumeral(values []rune, initial string) (*Numeral, error) {
 	return &number, nil
 }
 
+func valuesToPositions(values []rune) map [rune]int {
+	var pos=map[rune]int{}
+	for i := 0; i < len(values) ; i++ {
+		pos[values[i]]=i
+	}
+	return pos
+}
+
 // newDigit creates and initializes a new digit (ring).
 func newDigit(values []rune, state rune) (*ring.Ring, error) {
 	// initialize a new empty ring
@@ -174,8 +184,8 @@ func (n *Numeral) Decimal() int {
 		// get current ring.
 		r := d.Value.(*ring.Ring)
 		// get the index of the ring.
-		i := indexOf(r.Value.(rune), n.digitValues)
-
+		//i := indexOf(r.Value.(rune), n.digitValues)
+		i := n.digitPositions[r.Value.(rune)]
 		// Add digit's decimal counterpart to the decimal sum.
 		dec = dec + i*powInt(len(n.digitValues), di)
 		di++