diff --git a/LinkedList.java b/LinkedList.java
index 7836598c18ca0b770825087dc2deff812a699ec6..fa04bc82dd8d619c84cc92a4cf7923073fe5dea4 100644
--- a/LinkedList.java
+++ b/LinkedList.java
@@ -2,43 +2,98 @@ public class LinkedList <E> {
     private Node head;
 
     public LinkedList() {
-      head = null;
+        this.head = null;
     }
 
-    public void addToFront(E item) {
-        Node node = new Node(item);
+    //添加到头部
+    public void addToFront(E value) {
+        Node<E> node = new Node<>(value);
+        if (head != null) {
+            node.next = head;
+        }
+        head = node;
+    }
 
-        if (this.head == null) {
-            this.head = node;
-        } else{
-            Node temp = head;
-            this.head = node;
-            this.head.next = temp;
+    //添加到最后
+    public void addToRear(E value) {
+        Node<E> node = new Node<>(value);
+        if (head == null) {
+            head = node;
+        } else {
+            var temp = head;
+            while (temp.next != null) {
+                temp = temp.next;
+            }
+            temp.next = node;
         }
     }
 
+    // 打印所有节点
+    public void printItems() {
+        if (head != null) {
+            StringBuilder nodeListStr = new StringBuilder();
+            var temp = head;
+            while (temp != null) {
+                nodeListStr.append(temp.item).append(" ");
+                temp = temp.next;
+            }
+            System.out.println(nodeListStr);
+        } else {
+            System.out.println("空链表");
+        }
+    }
+
+    //删除节点 前提元素不重复
+    public void deleteItems(E value) {
+        if (head != null) {
+            String headStr = (String) head.item;
+            if (headStr.equals(value)){
+                head= head.next;
+                return;
+            }
+            var preNode  = head;
+            var curNode = head.next;
+            while (curNode != null) {
+                //这里全当字符串处理
+                String itemStr = (String) curNode.item;
+                if (itemStr.equals(value)) {
+                    //内容相同进行删除 结束循环
+                    preNode.next= curNode.next;
+                    break;
+                }
+                preNode=preNode.next;
+                curNode=preNode.next;
+            }
 
-    public void addToRear(E item) {
-        Node newNode = new Node(item);
-        if (this.head == null) {
-            this.head = newNode;
         } else {
-            
-            Node temp = this.head;
-            while(temp.next != null){
-              temp = temp.next;
+            System.out.println("链表为空，无法进行删除操作");
+        }
+    }
+
+    //判断节点是否存在
+    public boolean findItem(E value) {
+        var temp = head;
+        while (temp != null) {
+            //这里全当字符串处理
+            String itemStr = (String) temp.item;
+            if (itemStr.equals(value)) {
+                //内容相同节点存在结束循环
+                return true;
             }
-            temp.next = newNode;
+            temp = temp.next;
         }
+        return false;
     }
 
-    public void print() {
-        Node temp = this.head;
-        while(temp.next != null){
-            System.out.print(temp.item + " -> ");
+    //计算链表长度数值
+    public int size() {
+        int linkedListLength = 0;
+        var temp = head;
+        while (temp != null) {
+            linkedListLength++;
             temp = temp.next;
         }
-        System.out.println(temp.item);
+        return linkedListLength;
     }
-}
 
+}
\ No newline at end of file
diff --git a/Main.java b/Main.java
index 057428817fa315cf419ab3ea8cc74615dbf94f39..e287ed4a84d7c563553cdc42ca53bf9e92267e38 100644
--- a/Main.java
+++ b/Main.java
@@ -1,10 +1,19 @@
 class Main {
   public static void main(String[] args) {
-    LinkedList<Integer> ll = new LinkedList<Integer>();
-    ll.addToFront(1);
-    ll.addToFront(2);
-    ll.addToRear(3);
-    ll.print();
-    
+    var ll = new LinkedList<String>();
+    ll.printItems();
+    ll.addToFront("3");
+    ll.addToFront("5");
+    ll.printItems();
+    ll.addToRear("7");
+    ll.addToRear("2");
+    ll.printItems();
+    boolean itemExist = ll.findItem("6");
+    System.out.println(itemExist ? "节点存在" : "节点不存在");
+    System.out.println("链表长度为" + ll.size());
+    ll.printItems();
+    ll.deleteItems("1");
+    ll.deleteItems("9");
+    ll.printItems();
   }
 }
\ No newline at end of file
diff --git a/Node.java b/Node.java
index ed7a3524e3c608d2a479f484e240452ad34c5a51..fe64454a80aa32af96561d01573a106861693888 100644
--- a/Node.java
+++ b/Node.java
@@ -1,6 +1,6 @@
 public class Node<E> {
     E item;
-    Node<E> next = null;
+    Node next = null;
 
     Node(E item) {
         this.item = item;
diff --git a/lianbiao1/LinkedList1.java b/lianbiao1/LinkedList1.java
new file mode 100644
index 0000000000000000000000000000000000000000..04d63167bf94f1f167e4b4edeaae7cb81f161d0b
--- /dev/null
+++ b/lianbiao1/LinkedList1.java
@@ -0,0 +1,101 @@
+package lianbiao1;
+
+public class LinkedList1<E> {
+    private Node head;
+
+    public LinkedList1() {
+        this.head = null;
+    }
+
+    //添加到头部
+    public void addToFront(E value) {
+        Node<E> node = new Node<>(value);
+        if (head != null) {
+            node.next = head;
+        }
+        head = node;
+    }
+
+    //添加到最后
+    public void addToRear(E value) {
+        Node<E> node = new Node<>(value);
+        if (head == null) {
+            head = node;
+        } else {
+            var temp = head;
+            while (temp.next != null) {
+                temp = temp.next;
+            }
+            temp.next = node;
+        }
+    }
+
+    // 打印所有节点
+    public void printItems() {
+        if (head != null) {
+            StringBuilder nodeListStr = new StringBuilder();
+            var temp = head;
+            while (temp != null) {
+                nodeListStr.append(temp.item).append(" ");
+                temp = temp.next;
+            }
+            System.out.println(nodeListStr);
+        } else {
+            System.out.println("链表为空");
+        }
+    }
+
+    //删除节点 前提元素不重复
+    public void deleteItems(E value) {
+        if (head != null) {
+            String headStr = (String) head.item;
+            if (headStr.equals(value)){
+                head= head.next;
+                return;
+            }
+            var preNode  = head;
+            var curNode = head.next;
+            while (curNode != null) {
+                //这里全当字符串处理
+                String itemStr = (String) curNode.item;
+                if (itemStr.equals(value)) {
+                    //内容相同进行删除 结束循环
+                    preNode.next= curNode.next;
+                    break;
+                }
+                preNode=preNode.next;
+                curNode=preNode.next;
+            }
+
+        } else {
+            System.out.println("链表为空，无法删除操作");
+        }
+    }
+
+    //判断节点是否存在
+    public boolean findItem(E value) {
+        var temp = head;
+        while (temp != null) {
+            //这里全当字符串处理
+            String itemStr = (String) temp.item;
+            if (itemStr.equals(value)) {
+                //内容相同节点存在结束循环
+                return true;
+            }
+            temp = temp.next;
+        }
+        return false;
+    }
+
+    //计算链表长度数值
+    public int size() {
+        int linkedListLength = 0;
+        var temp = head;
+        while (temp != null) {
+            linkedListLength++;
+            temp = temp.next;
+        }
+        return linkedListLength;
+    }
+
+}
\ No newline at end of file
diff --git a/lianbiao1/Main.java b/lianbiao1/Main.java
new file mode 100644
index 0000000000000000000000000000000000000000..bb5ef75eab362cb10c56eb3a785be51a1d13f2fb
--- /dev/null
+++ b/lianbiao1/Main.java
@@ -0,0 +1,21 @@
+package lianbiao1;
+
+class Main {
+  public static void main(String[] args) {
+    var ll = new LinkedList1<String>();
+    ll.printItems();
+    ll.addToFront("3");
+    ll.addToFront("5");
+    ll.printItems();
+    ll.addToRear("7");
+    ll.addToRear("2");
+    ll.printItems();
+    boolean itemExist = ll.findItem("6");
+    System.out.println(itemExist ? "节点存在" : "节点不存在");
+    System.out.println("链表长度为" + ll.size());
+    ll.printItems();
+    ll.deleteItems("1");
+    ll.deleteItems("9");
+    ll.printItems();
+  }
+}
\ No newline at end of file
diff --git a/lianbiao1/Node.java b/lianbiao1/Node.java
new file mode 100644
index 0000000000000000000000000000000000000000..f36357814518deb33a8e7573d8d976772255b287
--- /dev/null
+++ b/lianbiao1/Node.java
@@ -0,0 +1,10 @@
+package lianbiao1;
+
+public class Node<E> {
+    E item;
+    Node next = null;
+
+    Node(E item) {
+        this.item = item;
+    }
+}
\ No newline at end of file
diff --git a/lianbiao2jianwei/LinkedList2.java b/lianbiao2jianwei/LinkedList2.java
new file mode 100644
index 0000000000000000000000000000000000000000..c570ba5ed625164b0faea955bdb88b8b1df32201
--- /dev/null
+++ b/lianbiao2jianwei/LinkedList2.java
@@ -0,0 +1,109 @@
+package lianbiao2jianwei;
+
+public class LinkedList2<E> {
+    private Node head;
+    private Node tail;
+
+    public LinkedList2() {
+        this.head = null;
+        this.tail = null;
+    }
+
+    //添加到头部
+    public void addToFront(E value) {
+        Node<E> node = new Node<>(value);
+        if (head == null) {
+            head = node;
+            tail = head;
+        } else {
+            node.next = head;
+            head = node;
+        }
+    }
+
+    //添加到最后
+    public void addToRear(E value) {
+        Node<E> node = new Node<>(value);
+        if (tail == null) {
+            tail = node;
+            head = tail;
+        } else {
+            tail.next = node;
+            tail = tail.next;
+        }
+    }
+
+    // 打印所有节点
+    public void printItems() {
+        if (head != null) {
+            String nodeListStr = "";
+            var temp = head;
+            while (temp != null) {
+                nodeListStr += (temp.item + "->");
+                temp = temp.next;
+            }
+            System.out.println(nodeListStr);
+        } else {
+            System.out.println("链表为空");
+        }
+    }
+
+    //删除节点 前提元素不重复
+    public void deleteItems(E value) {
+        if (head != null) {
+            String headStr = (String) head.item;
+            if (headStr.equals(value)) {
+                head = head.next;
+                return;
+            }
+            var preNode = head;
+            var curNode = head.next;
+            while (curNode != null) {
+                //这里全当字符串处理
+                String itemStr = (String) curNode.item;
+                if (itemStr.equals(value)) {
+                    if (curNode.next == null) {
+                        //删除最后一项
+                        //移动尾指针
+                        tail = preNode;
+                    }
+                    //内容相同进行删除 结束循环
+                    preNode.next = curNode.next;
+                    return;
+                }
+                preNode = preNode.next;
+                curNode = preNode.next;
+            }
+            System.out.println("无此节点，删除失败");
+        } else {
+            System.out.println("链表为空，无法删除操作");
+        }
+    }
+
+    //判断节点是否存在
+    public boolean findItem(E value) {
+        var temp = head;
+        while (temp != null) {
+            //这里全当字符串处理
+            String itemStr = (String) temp.item;
+            if (itemStr.equals(value)) {
+                //内容相同节点存在结束循环
+                return true;
+            }
+            temp = temp.next;
+        }
+        return false;
+    }
+
+    //计算链表长度数值
+    public int size() {
+        int linkedListLength = 0;
+        var temp = head;
+        while (temp != null) {
+            linkedListLength++;
+            temp = temp.next;
+        }
+        return linkedListLength;
+    }
+
+}
\ No newline at end of file
diff --git a/lianbiao2jianwei/Main.java b/lianbiao2jianwei/Main.java
new file mode 100644
index 0000000000000000000000000000000000000000..52b8d85bbd55a648b4a4237e852468905716f959
--- /dev/null
+++ b/lianbiao2jianwei/Main.java
@@ -0,0 +1,45 @@
+package lianbiao2jianwei;
+
+class Main {
+  public static void main(String[] args) {
+    //var ll = new LinkedList2<String>();
+   // ll.printItems();
+   // ll.addToFront("3");
+    //ll.addToFront("5");
+   // ll.printItems();
+   // ll.addToRear("7");
+   // ll.addToRear("2");
+   // ll.printItems();
+   // boolean itemExist = ll.findItem("6");
+   // System.out.println(itemExist ? "节点存在" : "节点不存在");
+   //System.out.println("链表长度为" + ll.size());
+   // ll.printItems();
+   // ll.deleteItems("1");
+    //ll.deleteItems("9");
+   // ll.printItems();
+    System.out.println("****************************************************");
+    System.out.println("2.实现带尾指针的链表");
+    var ll = new LinkedList2<String>();
+    ll.addToFront("1");
+    ll.addToFront("2");
+    ll.addToRear("3");
+    ll.addToRear("4");
+    ll.printItems();
+    boolean itemExist1 = ll.findItem("3");
+    System.out.println(itemExist1 ? "节点存在" : "节点不存在");
+    itemExist1 = ll.findItem("5");
+    System.out.println(itemExist1 ? "节点存在" : "节点不存在");
+    System.out.println("链表长度为" + ll.size());
+    ll.printItems();
+    ll.deleteItems("2");
+    ll.printItems();
+    ll.deleteItems("4");//测试删除尾结点
+    ll.printItems();
+    ll.addToRear("4");
+    ll.printItems();
+    ll.deleteItems("5");
+    ll.printItems();
+    System.out.println("****************************************************");
+    System.out.println("3.实现双向链表");
+  }
+}
\ No newline at end of file
diff --git a/lianbiao2jianwei/Node.java b/lianbiao2jianwei/Node.java
new file mode 100644
index 0000000000000000000000000000000000000000..0eb42c28dc06671dadfa702ac70a194c10418e37
--- /dev/null
+++ b/lianbiao2jianwei/Node.java
@@ -0,0 +1,10 @@
+package lianbiao2jianwei;
+
+public class Node<E> {
+    E item;
+    Node next = null;
+
+    Node(E item) {
+        this.item = item;
+    }
+}
\ No newline at end of file
diff --git a/lianbiao3shuangxiang/LinkedList3.java b/lianbiao3shuangxiang/LinkedList3.java
new file mode 100644
index 0000000000000000000000000000000000000000..39c122b588c1f644377f77c0ab7b24c99a2b9f05
--- /dev/null
+++ b/lianbiao3shuangxiang/LinkedList3.java
@@ -0,0 +1,108 @@
+package lianbiao3shuangxiang;
+
+public class LinkedList3<E> {
+    private Node head;
+    private Node tail;
+
+    public LinkedList3() {
+        this.head = null;
+        this.tail = null;
+    }
+
+    //添加到头部
+    public void addToFront(E value) {
+        Node<E> node;
+        node = new Node<>(value);
+        if (head == null) {
+            tail = node;
+        } else {
+            node.next = head;
+        }
+        head = node;
+    }
+
+    //添加到最后
+    public void addToRear(E value) {
+        Node<E> node = new Node<>(value);
+        if (head == null) {
+            head = node;
+        } else {
+            tail.next = node;
+        }
+        tail = node;
+    }
+
+    // 打印所有节点
+    public void printItems() {
+        if (head != null) {
+            String nodeListStr = "";
+            var temp = head;
+            while (temp != null) {
+                nodeListStr += (temp.item + "->");
+                temp = temp.next;
+            }
+            System.out.println(nodeListStr);
+        } else {
+            System.out.println("链表为空");
+        }
+    }
+
+    //删除节点 前提元素不重复
+    public void deleteItems(E value) {
+        if (head != null) {
+            String headStr = (String) head.item;
+            if (headStr.equals(value)) {
+                head = head.next;
+                return;
+            }
+            var preNode = head;
+            var curNode = head.next;
+            while (curNode != null) {
+                //这里全当字符串处理
+                String itemStr = (String) curNode.item;
+                if (itemStr.equals(value)) {
+                    if (curNode.next == null) {
+                        //删除最后一项
+                        //移动尾指针
+                        tail = preNode;
+                    }
+                    //内容相同进行删除 结束循环
+                    preNode.next = curNode.next;
+                    return;
+                }
+                preNode = preNode.next;
+                curNode = preNode.next;
+            }
+            System.out.println("无此节点，删除失败");
+        } else {
+            System.out.println("链表为空，无法删除操作");
+        }
+    }
+
+    //判断节点是否存在
+    public boolean findItem(E value) {
+        var temp = head;
+        while (temp != null) {
+            //这里全当字符串处理
+            String itemStr = (String) temp.item;
+            if (itemStr.equals(value)) {
+                //内容相同节点存在结束循环
+                return true;
+            }
+            temp = temp.next;
+        }
+        return false;
+    }
+
+    //计算链表长度数值
+    public int size() {
+        int linkedListLength = 0;
+        var temp = head;
+        while (temp != null) {
+            linkedListLength++;
+            temp = temp.next;
+        }
+        return linkedListLength;
+    }
+
+}
diff --git a/lianbiao3shuangxiang/Main.java b/lianbiao3shuangxiang/Main.java
new file mode 100644
index 0000000000000000000000000000000000000000..58521ec3a1a5b891487da7e988936d8b34d9635c
--- /dev/null
+++ b/lianbiao3shuangxiang/Main.java
@@ -0,0 +1,45 @@
+package lianbiao3shuangxiang;
+
+class Main {
+  public static void main(String[] args) {
+    //var ll = new LinkedList2<String>();
+   // ll.printItems();
+   // ll.addToFront("3");
+    //ll.addToFront("5");
+   // ll.printItems();
+   // ll.addToRear("7");
+   // ll.addToRear("2");
+   // ll.printItems();
+   // boolean itemExist = ll.findItem("6");
+   // System.out.println(itemExist ? "节点存在" : "节点不存在");
+   //System.out.println("链表长度为" + ll.size());
+   // ll.printItems();
+   // ll.deleteItems("1");
+    //ll.deleteItems("9");
+   // ll.printItems();
+    System.out.println("****************************************************");
+    System.out.println("2.实现带尾指针的链表");
+    var ll = new LinkedList3<String>();
+    ll.addToFront("1");
+    ll.addToFront("2");
+    ll.addToRear("3");
+    ll.addToRear("4");
+    ll.printItems();
+    boolean itemExist1 = ll.findItem("3");
+    System.out.println(itemExist1 ? "节点存在" : "节点不存在");
+    itemExist1 = ll.findItem("5");
+    System.out.println(itemExist1 ? "节点存在" : "节点不存在");
+    System.out.println("链表长度为" + ll.size());
+    ll.printItems();
+    ll.deleteItems("2");
+    ll.printItems();
+    ll.deleteItems("4");//测试删除尾结点
+    ll.printItems();
+    ll.addToRear("4");
+    ll.printItems();
+    ll.deleteItems("5");
+    ll.printItems();
+    System.out.println("****************************************************");
+    System.out.println("3.实现双向链表");
+  }
+}
\ No newline at end of file
diff --git a/lianbiao3shuangxiang/Node.java b/lianbiao3shuangxiang/Node.java
new file mode 100644
index 0000000000000000000000000000000000000000..d5a1103c3ba28c546f6ef465ffcf600f6904635b
--- /dev/null
+++ b/lianbiao3shuangxiang/Node.java
@@ -0,0 +1,10 @@
+package lianbiao3shuangxiang;
+
+public class Node<E> {
+    E item;
+    Node <E>  next = null;
+
+    Node(E item) {
+        this.item = item;
+    }
+}
\ No newline at end of file