添加题142，234，138

Author: ligecarryme

README.md

@@ -12,4 +12,9 @@
 
 #### 数据结构篇 🐢
 
-- [二叉树](https://github.com/ligecarryme/algorithm-pattern-JavaScript/blob/master/%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E7%AF%87/%E4%BA%8C%E5%8F%89%E6%A0%91.md)
+- [二叉树](https://github.com/ligecarryme/algorithm-pattern-JavaScript/blob/master/%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E7%AF%87/%E4%BA%8C%E5%8F%89%E6%A0%91.md)
+- [链表](https://github.com/ligecarryme/algorithm-pattern-JavaScript/blob/master/%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E7%AF%87/%E9%93%BE%E8%A1%A8.md)
+
+- [栈和队列](https://github.com/ligecarryme/algorithm-pattern-JavaScript/blob/master/%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E7%AF%87/%E6%A0%88%E5%92%8C%E9%98%9F%E5%88%97.md)
+- [二进制](https://github.com/ligecarryme/algorithm-pattern-JavaScript/blob/master/%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E7%AF%87/%E4%BA%8C%E8%BF%9B%E5%88%B6.md)
+

数据结构篇/链表.md

@@ -204,6 +204,58 @@ var partition = function(head, x) {
 
 ##### [148. 排序链表](https://leetcode-cn.com/problems/sort-list/)
 
+给你链表的头结点 `head` ，请将其按 **升序** 排列并返回 **排序后的链表** 。`O(nlogn)`时间复杂度，常数级空间。
+
+```js
+var sortList = function (head) {
+    return mergeSort(head)
+};
+
+const findMidNode = head => {
+    let slow = head
+    let fast = head.next
+    while (fast !== null && fast.next !== null) {
+        slow = slow.next
+        fast = fast.next.next
+    }
+    return slow
+}
+
+const mergeTwoList = (l1, l2) => {
+    const dummy = new ListNode(0)
+    let p = dummy
+    while (l1 !== null && l2 !== null) {
+        if (l1.val < l2.val) {
+            p.next = l1
+            l1 = l1.next
+        } else {
+            p.next = l2
+            l2 = l2.next
+        }
+        p = p.next
+    }
+    if (l1 !== null) { // l1不为空，p指向剩下的链表
+        p.next = l1
+    }
+    if (l2 !== null) {
+        p.next = l2
+    }
+    return dummy.next
+}
+
+const mergeSort = head => {
+    if (head === null || head.next === null) {
+        return head
+    }
+    let mid = findMidNode(head)
+    let tail = mid.next
+    mid.next = null
+    let left = mergeSort(head)
+    let right = mergeSort(tail)
+    return mergeTwoList(left, right)
+}
+```
+
 ##### [143. 重排链表](https://leetcode-cn.com/problems/reorder-list/)
 
 给定一个单链表 L：L0→L1→…→Ln-1→Ln ，
@@ -253,3 +305,136 @@ var hasCycle = function (head) {
 }
 ```
 
+##### [142. 环形链表 II](https://leetcode-cn.com/problems/linked-list-cycle-ii/)
+
+给定一个链表，返回链表开始入环的第一个节点。 如果链表无环，则返回 `null`。
+
+```js
+var detectCycle = function (head) {
+    let visited = new Set()  //使用哈希表，空间复杂度O(n)
+    while (head !== null) {
+        if(visited.has(head)){
+            return head
+        }
+        visited.add(head)
+        head = head.next
+    }
+    return null
+};
+```
+
+```js
+var detectCycle = function (head) {  
+    if (head === null || head.next === null) {
+        return null
+    }
+    let slow = head
+    let fast = head.next
+    while(fast !== null && fast.next !== null){
+        if(fast === slow) { //数学推导，看官网题解
+            slow = slow.next
+            fast = head
+            while(fast !== slow){ 
+                slow = slow.next
+                fast = fast.next
+            }
+            return slow
+        }
+        slow = slow.next
+        fast = fast.next.next
+    }
+    return null
+};
+```
+
+##### [234. 回文链表](https://leetcode-cn.com/problems/palindrome-linked-list/)
+
+请判断一个链表是否为回文链表。
+
+```js
+var isPalindrome = function (head) {
+    if (head === null || head.next === null) {
+        return true
+    }
+    let slow = head
+    let fast = head.next
+    while (fast !== null && fast.next !== null) {
+        slow = slow.next
+        fast = fast.next.next
+    }
+    let tail = reverseList(slow.next)
+    slow.next = null
+    while (head !== null && tail !== null) {
+        if (head.val !== tail.val) {
+            return false
+        }
+        head = head.next
+        tail = tail.next
+    }
+    return true
+};
+
+const reverseList = head => {
+    if (head === null) {
+        return head
+    }
+    const dummy = new ListNode(0)
+    let prev = head
+    while (prev !== null) {  //头插法
+        let temp = prev
+        prev = prev.next
+        temp.next = dummy.next
+        dummy.next = temp
+    }
+    return dummy.next
+}
+```
+
+##### [138. 复制带随机指针的链表](https://leetcode-cn.com/problems/copy-list-with-random-pointer/)
+
+给你一个长度为 `n` 的链表，每个节点包含一个额外增加的随机指针 `random` ，该指针可以指向链表中的任何节点或空节点。
+
+```js
+var copyRandomList = function (head) {
+    if (head === null) {
+        return head
+    }
+    let cur = head
+    while (cur !== null) {
+        const clone = new Node(cur.val, cur.next, cur.random)
+        const temp = cur.next
+        cur.next = clone
+        cur = temp
+    }
+    cur = head
+    while (cur !== null) {
+        if (cur.random !== null) {
+            cur.next.random = cur.random.next
+        }
+        cur = cur.next.next
+    }
+    cur = head
+    let cloneHead = cur.next
+    while (cur !== null && cur.next !== null) {
+        const temp = cur.next
+        cur.next = cur.next.next
+        cur = temp
+    }
+    return cloneHead
+}; 
+```
+
+## 练习
+
+-  [remove-duplicates-from-sorted-list](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list/)
+-  [remove-duplicates-from-sorted-list-ii](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii/)
+-  [reverse-linked-list](https://leetcode-cn.com/problems/reverse-linked-list/)
+-  [reverse-linked-list-ii](https://leetcode-cn.com/problems/reverse-linked-list-ii/)
+-  [merge-two-sorted-lists](https://leetcode-cn.com/problems/merge-two-sorted-lists/)
+-  [partition-list](https://leetcode-cn.com/problems/partition-list/)
+-  [sort-list](https://leetcode-cn.com/problems/sort-list/)
+-  [reorder-list](https://leetcode-cn.com/problems/reorder-list/)
+-  [linked-list-cycle](https://leetcode-cn.com/problems/linked-list-cycle/)
+-  [linked-list-cycle-ii](https://leetcode-cn.com/problems/linked-list-cycle-ii/)
+-  [palindrome-linked-list](https://leetcode-cn.com/problems/palindrome-linked-list/)
+-  [copy-list-with-random-pointer](https://leetcode-cn.com/problems/copy-list-with-random-pointer/)