24: pandigital products

24_lexicographic_permutations/main.go

@@ -10,7 +10,7 @@ var nums = []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
 func main() {
 	var facs []int
 	for _, i := range nums {
-		n, _ := findPermutation(i, i)
+		n := findFacs(i)
 		facs = append(facs, n)
 	}
 	fmt.Println("facs:", facs)
@@ -30,13 +30,10 @@ func findNPermutation(n int, src []int, facs []int) string {
 	return ret
 }
 
-func findPermutation(n, m int) (int, error) {
-	if m > n {
-		return 0, fmt.Errorf("m=%d cannot be larger than n=%d", m, n)
-	}
+func findFacs(n int) int {
 	p := 1
-	for i := n - m + 1; i <= n; i++ {
+	for i := 1; i <= n; i++ {
 		p *= i
 	}
-	return p, nil
+	return p
 }