diff --git a/README.md b/README.md
index 5896e58..ff79165 100644
--- a/README.md
+++ b/README.md
@@ -81,19 +81,41 @@ import "github.com/duke-git/lancet/v2/algorithm"
 ```
 
 #### Function list:
-
--   [BubbleSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#BubbleSort)
--   [CountSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#CountSort)
--   [HeapSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#HeapSort)
--   [InsertionSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#InsertionSort)
--   [MergeSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#MergeSort)
--   [QuickSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#QuickSort)
--   [SelectionSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#SelectionSort)
--   [ShellSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#ShellSort)
--   [BinarySearch](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#BinarySearch)
--   [BinaryIterativeSearch](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#BinaryIterativeSearch)
--   [LinearSearch](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#LinearSearch)
--   [LRUCache](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#LRUCache)
+- **<big>BubbleSort</big>** : sorts slice with bubble sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#BubbleSort)] 
+[[play](https://go.dev/play/p/GNdv7Jg2Taj)]
+- **<big>CountSort</big>** : sorts slice with bubble sort algorithm, don't change original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#CountSort)] 
+[[play](https://go.dev/play/p/tB-Umgm0DrP)]
+- **<big>HeapSort</big>** : sorts slice with heap sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#HeapSort)] 
+[[play](https://go.dev/play/p/u6Iwa1VZS_f)]
+- **<big>InsertionSort</big>** : sorts slice with insertion sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#InsertionSort)] 
+[[play](https://go.dev/play/p/G5LJiWgJJW6)]
+- **<big>MergeSort</big>** : sorts slice with merge sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#MergeSort)] 
+[[play](https://go.dev/play/p/ydinn9YzUJn)]
+- **<big>QuickSort</big>** : sorts slice with quick sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#QuickSort)] 
+[[play](https://go.dev/play/p/7Y7c1Elk3ax)]
+- **<big>SelectionSort</big>** : sorts slice with selection sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#SelectionSort)] 
+[[play](https://go.dev/play/p/oXovbkekayS)]
+- **<big>ShellSort</big>** : sorts slice with shell sort algorithm, will change the original slice. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#ShellSort)] 
+[[play](https://go.dev/play/p/3ibkszpJEu3)]
+- **<big>BinarySearch</big>** : returns the index of target within a sorted slice, use binary search (recursive call itself). 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#BinarySearch)]
+[[play](https://go.dev/play/p/t6MeGiUSN47)]
+- **<big>BinaryIterativeSearch</big>** : returns the index of target within a sorted slice, use binary search (no recursive). 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#BinaryIterativeSearch)]
+[[play](https://go.dev/play/p/Anozfr8ZLH3)]
+- **<big>LinearSearch</big>** : returns the index of target in slice base on equal function. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#LinearSearch)]
+- **<big>LRUCache</big>** : implements memory cache with lru algorithm. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm.md#LRUCache)]
+[[play](https://go.dev/play/p/-EZjgOURufP)]
 
 ### 2. Concurrency package contain some functions to support concurrent programming. eg, goroutine, channel, async.
 
diff --git a/README_zh-CN.md b/README_zh-CN.md
index 0898f30..85ee991 100644
--- a/README_zh-CN.md
+++ b/README_zh-CN.md
@@ -79,19 +79,41 @@ import "github.com/duke-git/lancet/v2/algorithm"
 ```
 
 #### Function list:
-
--   [BubbleSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#BubbleSort)
--   [CountSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#CountSort)
--   [HeapSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#HeapSort)
--   [InsertionSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#InsertionSort)
--   [MergeSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#MergeSort)
--   [QuickSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#QuickSort)
--   [SelectionSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#SelectionSort)
--   [ShellSort](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#ShellSort)
--   [BinarySearch](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#BinarySearch)
--   [BinaryIterativeSearch](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#BinaryIterativeSearch)
--   [LinearSearch](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#LinearSearch)
--   [LRUCache](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#LRUCache)
+- **<big>BubbleSort</big>** : 使用冒泡排序算法对切片进行排序。
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#BubbleSort)] 
+[[play](https://go.dev/play/p/GNdv7Jg2Taj)]
+- **<big>CountSort</big>** : 使用计数排序算法对切片进行排序。不改变原数据。
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#CountSort)] 
+[[play](https://go.dev/play/p/tB-Umgm0DrP)]
+- **<big>HeapSort</big>** : 使用堆排序算法对切片进行排序。 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#HeapSort)] 
+[[play](https://go.dev/play/p/u6Iwa1VZS_f)]
+- **<big>InsertionSort</big>** : 使用插入排序算法对切片进行排序。
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#InsertionSort)] 
+[[play](https://go.dev/play/p/G5LJiWgJJW6)]
+- **<big>MergeSort</big>** : 使用合并排序算法对切片进行排序。 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#MergeSort)] 
+[[play](https://go.dev/play/p/ydinn9YzUJn)]
+- **<big>QuickSort</big>** : 使用快速排序算法对切片进行排序。 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#QuickSort)] 
+[[play](https://go.dev/play/p/7Y7c1Elk3ax)]
+- **<big>SelectionSort</big>** : 使用选择排序算法对切片进行排序。
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#SelectionSort)] 
+[[play](https://go.dev/play/p/oXovbkekayS)]
+- **<big>ShellSort</big>** : 使用希尔排序算法对切片进行排序。 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#ShellSort)] 
+[[play](https://go.dev/play/p/3ibkszpJEu3)]
+- **<big>BinarySearch</big>** : 返回排序切片中目标值的索引，使用二分搜索（递归调用）。
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#BinarySearch)]
+[[play](https://go.dev/play/p/t6MeGiUSN47)]
+- **<big>BinaryIterativeSearch</big>** :返回排序切片中目标值的索引，使用二分搜索（非递归）。 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#BinaryIterativeSearch)]
+[[play](https://go.dev/play/p/Anozfr8ZLH3)]
+- **<big>LinearSearch</big>** : 基于传入的相等函数返回切片中目标值的索引。（线性查找）
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#LinearSearch)]
+- **<big>LRUCache</big>** : 应用lru算法实现内存缓存. 
+[[doc](https://github.com/duke-git/lancet/blob/main/docs/algorithm_zh-CN.md#LRUCache)]
+[[play](https://go.dev/play/p/-EZjgOURufP)]
 
 ### 2. concurrency包含一些支持并发编程的功能。例如：goroutine, channel, async 等。
 
diff --git a/algorithm/search.go b/algorithm/search.go
index 73a01b7..b44b1a6 100644
--- a/algorithm/search.go
+++ b/algorithm/search.go
@@ -1,7 +1,7 @@
 // Copyright 2021 dudaodong@gmail.com. All rights reserved.
 // Use of this source code is governed by MIT license
 
-// Package algorithm contain some basic algorithm functions. eg. sort, search, list, linklist, stack, queue, tree, graph. TODO
+// Package algorithm contain some basic algorithm functions. eg. sort, search, list, linklist, stack, queue, tree, graph.
 package algorithm
 
 import "github.com/duke-git/lancet/v2/lancetconstraints"
diff --git a/algorithm/sort.go b/algorithm/sort.go
index 5dee7f2..aaf2f45 100644
--- a/algorithm/sort.go
+++ b/algorithm/sort.go
@@ -1,7 +1,6 @@
 // Copyright 2021 dudaodong@gmail.com. All rights reserved.
 // Use of this source code is governed by MIT license
 
-// Package algorithm contain some basic algorithm functions. eg. sort, search
 package algorithm
 
 import "github.com/duke-git/lancet/v2/lancetconstraints"
@@ -35,7 +34,7 @@ func InsertionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 }
 
 // SelectionSort applys the selection sort algorithm to sort the collection, will change the original collection data.
-// Play:
+// Play: https://go.dev/play/p/oXovbkekayS
 func SelectionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	for i := 0; i < len(slice); i++ {
 		min := i
diff --git a/docs/algorithm.md b/docs/algorithm.md
index 7ff2da6..82173b8 100644
--- a/docs/algorithm.md
+++ b/docs/algorithm.md
@@ -570,6 +570,8 @@ func main() {
 func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V]
 func (l *LRUCache[K, V]) Get(key K) (V, bool)
 func (l *LRUCache[K, V]) Put(key K, value V)
+func (l *LRUCache[K, V]) Delete(key K) bool
+func (l *LRUCache[K, V]) Len() int
 ```
 <b>Example:</b>
 
@@ -586,10 +588,14 @@ func main() {
 
     cache.Put(1, 1)
     cache.Put(2, 2)
+    cache.Put(3, 3)
 
-    _, ok := cache.Get(0) // ok -> false
+    fmt.Println(cache.Len()) // 3
 
-    v, ok := cache.Get(1) // v->1, ok->true
+    v, ok := cache.Get(1)
+    fmt.Println(v, ok) // 1 true
 
+    ok = cache.Delete(1)
+    fmt.Println(ok) // true
 }
 ```
\ No newline at end of file
diff --git a/docs/algorithm_zh-CN.md b/docs/algorithm_zh-CN.md
index d0dfc4e..771988a 100644
--- a/docs/algorithm_zh-CN.md
+++ b/docs/algorithm_zh-CN.md
@@ -570,6 +570,8 @@ func main() {
 func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V]
 func (l *LRUCache[K, V]) Get(key K) (V, bool)
 func (l *LRUCache[K, V]) Put(key K, value V)
+func (l *LRUCache[K, V]) Delete(key K) bool
+func (l *LRUCache[K, V]) Len() int
 ```
 <b>Example:</b>
 
@@ -586,10 +588,14 @@ func main() {
 
     cache.Put(1, 1)
     cache.Put(2, 2)
+    cache.Put(3, 3)
 
-    _, ok := cache.Get(0) // ok -> false
+    fmt.Println(cache.Len()) // 3
 
-    v, ok := cache.Get(1) // v->1, ok->true
+    v, ok := cache.Get(1)
+    fmt.Println(v, ok) // 1 true
 
+    ok = cache.Delete(1)
+    fmt.Println(ok) // true
 }
 ```
\ No newline at end of file