Stablize SkipList benchmark (#70)

compute.go

@@ -25,9 +25,8 @@ func AverageAs[R, T Numeric](a []T) R {
 
 // Average returns the average value of a.
 func Average[T Numeric](a []T) T {
-	var x T
-	var i interface{} = x
-	switch i.(type) {
+	var zero T // NOTE: convert 0 to interface have no malloc
+	switch any(zero).(type) {
 	case int, int8, uint8, int16, uint16, int32, uint32:
 		return T(AverageAs[int64](a))
 	case uint64:

skiplist_bench_test.go

@@ -110,6 +110,7 @@ func BenchmarkSkipList_Find(b *testing.B) {
 
 func BenchmarkSkipListString(b *testing.B) {
 	sl := NewSkipList[string, int]()
+	sl.rander.Seed(0)
 	var a []string
 	for i := 0; i < benchBatchSize; i++ {
 		a = append(a, strconv.Itoa(benchInitSize+i))

skiplist_test.go

@@ -170,6 +170,7 @@ func TestSkipList_Insert_Dup(t *testing.T) {
 
 func newSkipListN(n int) *SkipList[int, int] {
 	sl := NewSkipList[int, int]()
+	sl.rander.Seed(0)
 	for i := 0; i < n; i++ {
 		sl.Insert(i, i)
 	}