diff --git a/day09/day.go b/day09/day.go
index df4b106..7cf60f4 100644
--- a/day09/day.go
+++ b/day09/day.go
@@ -7,9 +7,9 @@ import (
 	"tools"
 )
 
-func getDistanceMap(input []string) ([]string, map[string]map[string]int) {
+func getDistanceMap(input []string) ([]interface{}, map[string]map[string]int) {
 	distances := make(map[string]map[string]int)
-	var retCities []string
+	var retCities []interface{}
 
 	for _, line := range input {
 		distDescr := strings.Split(line, " = ")
@@ -31,42 +31,14 @@ func getDistanceMap(input []string) ([]string, map[string]map[string]int) {
 	return retCities, distances
 }
 
-func cityPermutations(slice []string) (permutations [][]string) {
-	if len(slice) == 1 {
-		return [][]string{slice}
-	} else if len(slice) == 2 {
-		return [][]string{
-			{
-				slice[0],
-				slice[1],
-			},
-			{
-				slice[1],
-				slice[0],
-			},
-		}
-	} else {
-		for i := range slice {
-			newSlice := make([]string, i)
-			copy(newSlice, slice[:i])
-			newSlice = append(newSlice, slice[i+1:]...)
-			subPermutations := cityPermutations(newSlice)
-			for _, subPermutation := range subPermutations {
-				permutations = append(permutations, append([]string{slice[i]}, subPermutation...))
-			}
-		}
-		return permutations
-	}
-}
-
-func getMinMaxDistances(permutations [][]string, distances map[string]map[string]int) (int, int) {
+func getMinMaxDistances(permutations [][]interface{}, distances map[string]map[string]int) (int, int) {
 	minDistance := math.MaxInt32
 	maxDistance := 0
 
 	for _, v := range permutations {
 		thisDistance := 0
 		for i := 0; i < len(v)-1; i++ {
-			thisDistance += distances[v[i]][v[i+1]]
+			thisDistance += distances[v[i].(string)][v[i+1].(string)]
 		}
 		if thisDistance < minDistance {
 			minDistance = thisDistance
@@ -81,14 +53,14 @@ func getMinMaxDistances(permutations [][]string, distances map[string]map[string
 
 func Part1(puzzle tools.AoCPuzzle) interface{} {
 	cities, distances := getDistanceMap(puzzle.GetInputArray())
-	minDistance, _ := getMinMaxDistances(cityPermutations(cities), distances)
+	minDistance, _ := getMinMaxDistances(tools.Permutations(cities), distances)
 
 	return minDistance
 }
 
 func Part2(puzzle tools.AoCPuzzle) interface{} {
 	cities, distances := getDistanceMap(puzzle.GetInputArray())
-	_, maxDistance := getMinMaxDistances(cityPermutations(cities), distances)
+	_, maxDistance := getMinMaxDistances(tools.Permutations(cities), distances)
 
 	return maxDistance
 }
diff --git a/day13/day.go b/day13/day.go
index 4bbe60f..220e44d 100644
--- a/day13/day.go
+++ b/day13/day.go
@@ -7,9 +7,9 @@ import (
 	"tools"
 )
 
-func getMoodMap(input []string, addYourself bool) ([]string, map[string]map[string]int) {
+func getMoodMap(input []string, addYourself bool) ([]interface{}, map[string]map[string]int) {
 	moodMap := make(map[string]map[string]int)
-	var people []string
+	var people []interface{}
 
 	for _, line := range input {
 		moodDescr := strings.Split(line, " ")
@@ -34,35 +34,7 @@ func getMoodMap(input []string, addYourself bool) ([]string, map[string]map[stri
 	return people, moodMap
 }
 
-func seatingPermutations(slice []string) (permutations [][]string) {
-	if len(slice) == 1 {
-		return [][]string{slice}
-	} else if len(slice) == 2 {
-		return [][]string{
-			{
-				slice[0],
-				slice[1],
-			},
-			{
-				slice[1],
-				slice[0],
-			},
-		}
-	} else {
-		for i := range slice {
-			newSlice := make([]string, i)
-			copy(newSlice, slice[:i])
-			newSlice = append(newSlice, slice[i+1:]...)
-			subPermutations := seatingPermutations(newSlice)
-			for _, subPermutation := range subPermutations {
-				permutations = append(permutations, append([]string{slice[i]}, subPermutation...))
-			}
-		}
-		return permutations
-	}
-}
-
-func getMinMaxMoods(permutations [][]string, moodMap map[string]map[string]int) (int, int) {
+func getMinMaxMoods(permutations [][]interface{}, moodMap map[string]map[string]int) (int, int) {
 	minMood := math.MaxInt32
 	maxMood := 0
 
@@ -73,8 +45,8 @@ func getMinMaxMoods(permutations [][]string, moodMap map[string]map[string]int)
 			if j == len(v) {
 				j = 0
 			}
-			thisMood += moodMap[v[i]][v[j]]
-			thisMood += moodMap[v[j]][v[i]]
+			thisMood += moodMap[v[i].(string)][v[j].(string)]
+			thisMood += moodMap[v[j].(string)][v[i].(string)]
 		}
 		if thisMood < minMood {
 			minMood = thisMood
@@ -89,14 +61,14 @@ func getMinMaxMoods(permutations [][]string, moodMap map[string]map[string]int)
 
 func Part1(puzzle tools.AoCPuzzle) interface{} {
 	people, moodMap := getMoodMap(puzzle.GetInputArray(), false)
-	_, maxMood := getMinMaxMoods(seatingPermutations(people), moodMap)
+	_, maxMood := getMinMaxMoods(tools.Permutations(people), moodMap)
 
 	return maxMood
 }
 
 func Part2(puzzle tools.AoCPuzzle) interface{} {
 	people, moodMap := getMoodMap(puzzle.GetInputArray(), true)
-	_, maxMood := getMinMaxMoods(seatingPermutations(people), moodMap)
+	_, maxMood := getMinMaxMoods(tools.Permutations(people), moodMap)
 
 	return maxMood
 }