diff --git a/util/math.go b/util/math.go
index dd659bc..395f6ea 100644
--- a/util/math.go
+++ b/util/math.go
@@ -2,10 +2,6 @@ package util
 
 import "math"
 
-func FloorDiv(a, b int32) int32 {
-	return (a - ((a%b + b) % b)) / b
-}
-
 func BpeByNum(x float64) uint8 {
 	return uint8(math.Ceil(math.Log2(x)))
 }
diff --git a/util/must.go b/util/must.go
index 6ecbe3b..82b9b29 100644
--- a/util/must.go
+++ b/util/must.go
@@ -1,21 +1,8 @@
 package util
 
-func MustOk[T any](v T, ok bool) T {
-	if !ok {
-		panic("not ok")
-	}
-	return v
-}
-
 func MustT[T any](v T, err error) T {
 	if err != nil {
 		panic(err)
 	}
 	return v
 }
-
-func Must(err error) {
-	if err != nil {
-		panic(err)
-	}
-}
diff --git a/util/slices.go b/util/slices.go
index 70987f5..4f092bd 100644
--- a/util/slices.go
+++ b/util/slices.go
@@ -1,87 +1,11 @@
 package util
 
-import (
-	"cmp"
-	"math/rand/v2"
-	"slices"
-)
-
-func ShuffleSlice[T any](s []T) (ret []T) {
-	rand.Shuffle(len(s), func(i, j int) { s[i], s[j] = s[j], s[i] })
-	return s
-}
-
-func CountSlice[T comparable](s []T, o T) (ret int) {
-	for _, v := range s {
-		if v == o {
-			ret++
-		}
-	}
-	return
-}
-
-func GetUniqueSlice[T comparable](s []T) (unique map[T]struct{}) {
-	unique = make(map[T]struct{})
-	for _, v := range s {
-		if _, ok := unique[v]; !ok {
-			unique[v] = struct{}{}
-		}
-	}
-	return
-}
-
-func CountUniqueSlice[T comparable](s []T) (ret int) {
-	return len(GetUniqueSlice(s))
-}
-
-func MakeSingleValuedSlice[T any](v T, n int) (ret []T) {
-	ret = make([]T, n)
-	for i := range ret {
-		ret[i] = v
-	}
-	return
-}
-
-func SetToSlice[T comparable](set map[T]struct{}) (slice []T) {
-	slice = make([]T, 0, len(set))
-	for k := range set {
-		slice = append(slice, k)
-	}
-	return
-}
-
-func SetToSliceOrdered[T cmp.Ordered](set map[T]struct{}) (slice []T) {
-	slice = SetToSlice(set)
-	slices.Sort(slice)
-	return
-}
-
-func MinSlice[T cmp.Ordered](s []T) (ret T) {
-	ret = s[0]
-	for _, v := range s[1:] {
-		if v < ret {
-			ret = v
-		}
-	}
-	return
-}
-
 type Numeric interface {
 	~int | ~int8 | ~int16 | ~int32 | ~int64 |
 		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
 		~float32 | ~float64
 }
 
-func SliceRange[T Numeric](s, e T) (ret []T) {
-	if s > e {
-		return
-	}
-	for v := s; v < e; v++ {
-		ret = append(ret, v)
-	}
-	return
-}
-
 func IsLastElement[T comparable](s []T, e T) bool {
 	return len(s) > 0 && s[len(s)-1] == e
 }