"content":"<p>Design your implementation of the linked list. You can choose to use a singly or doubly linked list.<br />\nA node in a singly linked list should have two attributes: <code>val</code> and <code>next</code>. <code>val</code> is the value of the current node, and <code>next</code> is a pointer/reference to the next node.<br />\nIf you want to use the doubly linked list, you will need one more attribute <code>prev</code> to indicate the previous node in the linked list. Assume all nodes in the linked list are <strong>0-indexed</strong>.</p>\n\n<p>Implement the <code>MyLinkedList</code> class:</p>\n\n<ul>\n\t<li><code>MyLinkedList()</code> Initializes the <code>MyLinkedList</code> object.</li>\n\t<li><code>int get(int index)</code> Get the value of the <code>index<sup>th</sup></code> node in the linked list. If the index is invalid, return <code>-1</code>.</li>\n\t<li><code>void addAtHead(int val)</code> Add a node of value <code>val</code> before the first element of the linked list. After the insertion, the new node will be the first node of the linked list.</li>\n\t<li><code>void addAtTail(int val)</code> Append a node of value <code>val</code> as the last element of the linked list.</li>\n\t<li><code>void addAtIndex(int index, int val)</code> Add a node of value <code>val</code> before the <code>index<sup>th</sup></code> node in the linked list. If <code>index</code> equals the length of the linked list, the node will be appended to the end of the linked list. If <code>index</code> is greater than the length, the node <strong>will not be inserted</strong>.</li>\n\t<li><code>void deleteAtIndex(int index)</code> Delete the <code>index<sup>th</sup></code> node in the linked list, if the index is valid.</li>\n</ul>\n\n<p> </p>\n<p><strong class=\"example\">Example 1:</strong></p>\n\n<pre>\n<strong>Input</strong>\n["MyLinkedList", "addAtHead", "addAtTail", "addAtIndex", "get", "deleteAtIndex", "get"]\n[[], [1], [3], [1, 2], [1], [1], [1]]\n<strong>Output</strong>\n[null, null, null, null, 2, null, 3]\n\n<strong>Explanation</strong>\nMyLinkedList myLinkedList = new MyLinkedList();\nmyLinkedList.addAtHead(1);\nmyLinkedList.addAtTail(3);\nmyLinkedList.addAtIndex(1, 2); // linked list becomes 1->2->3\nmyLinkedList.get(1); // return 2\nmyLinkedList.deleteAtIndex(1); // now the linked list is 1->3\nmyLinkedList.get(1); // return 3\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>0 <= index, val <= 1000</code></li>\n\t<li>Please do not use the built-in LinkedList library.</li>\n\t<li>At most <code>2000</code> calls will be made to <code>get</code>, <code>addAtHead</code>, <code>addAtTail</code>, <code>addAtIndex</code> and <code>deleteAtIndex</code>.</li>\n</ul>\n",
"code":"public class MyLinkedList {\n\n public MyLinkedList() {\n \n }\n \n public int Get(int index) {\n \n }\n \n public void AddAtHead(int val) {\n \n }\n \n public void AddAtTail(int val) {\n \n }\n \n public void AddAtIndex(int index, int val) {\n \n }\n \n public void DeleteAtIndex(int index) {\n \n }\n}\n\n/**\n * Your MyLinkedList object will be instantiated and called as such:\n * MyLinkedList obj = new MyLinkedList();\n * int param_1 = obj.Get(index);\n * obj.AddAtHead(val);\n * obj.AddAtTail(val);\n * obj.AddAtIndex(index,val);\n * obj.DeleteAtIndex(index);\n */",
"code":"class MyLinkedList() {\n\n fun get(index: Int): Int {\n \n }\n\n fun addAtHead(`val`: Int) {\n \n }\n\n fun addAtTail(`val`: Int) {\n \n }\n\n fun addAtIndex(index: Int, `val`: Int) {\n \n }\n\n fun deleteAtIndex(index: Int) {\n \n }\n\n}\n\n/**\n * Your MyLinkedList object will be instantiated and called as such:\n * var obj = MyLinkedList()\n * var param_1 = obj.get(index)\n * obj.addAtHead(`val`)\n * obj.addAtTail(`val`)\n * obj.addAtIndex(index,`val`)\n * obj.deleteAtIndex(index)\n */",
"code":"-spec my_linked_list_init_() -> any().\nmy_linked_list_init_() ->\n .\n\n-spec my_linked_list_get(Index :: integer()) -> integer().\nmy_linked_list_get(Index) ->\n .\n\n-spec my_linked_list_add_at_head(Val :: integer()) -> any().\nmy_linked_list_add_at_head(Val) ->\n .\n\n-spec my_linked_list_add_at_tail(Val :: integer()) -> any().\nmy_linked_list_add_at_tail(Val) ->\n .\n\n-spec my_linked_list_add_at_index(Index :: integer(), Val :: integer()) -> any().\nmy_linked_list_add_at_index(Index, Val) ->\n .\n\n-spec my_linked_list_delete_at_index(Index :: integer()) -> any().\nmy_linked_list_delete_at_index(Index) ->\n .\n\n\n%% Your functions will be called as such:\n%% my_linked_list_init_(),\n%% Param_1 = my_linked_list_get(Index),\n%% my_linked_list_add_at_head(Val),\n%% my_linked_list_add_at_tail(Val),\n%% my_linked_list_add_at_index(Index, Val),\n%% my_linked_list_delete_at_index(Index),\n\n%% my_linked_list_init_ will be called before every test case, in which you can do some necessary initializations.",
"envInfo":"{\"cpp\": [\"C++\", \"<p>Compiled with <code> clang 11 </code> using the latest C++ 20 standard.</p>\\r\\n\\r\\n<p>Your code is compiled with level two optimization (<code>-O2</code>). <a href=\\\"https://github.com/google/sanitizers/wiki/AddressSanitizer\\\" target=\\\"_blank\\\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\\r\\n\\r\\n<p>Most standard library headers are already included automatically for your convenience.</p>\"], \"java\": [\"Java\", \"<p><code>OpenJDK 17</code>. Java 8 features such as lambda expressions and stream API can be used. </p>\\r\\n\\r\\n<p>Most standard library headers are already included automatically for your convenience.</p>\\r\\n<p>Includes <code>Pair</code> class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.</p>\"], \"python\": [\"Python\", \"<p><code>Python 2.7.12</code>.</p>\\r\\n\\r\\n<p>Most libraries are already imported automatically for your convenience, such as <a href=\\\"https://docs.python.org/2/library/array.html\\\" target=\\\"_blank\\\">array</a>, <a href=\\\"https://docs.python.org/2/library/bisect.html\\\" target=\\\"_blank\\\">bisect</a>, <a href=\\\"https://docs.python.org/2/library/collections.html\\\" target=\\\"_blank\\\">collections</a>. If you need more libraries, you can import it yourself.</p>\\r\\n\\r\\n<p>For Map/TreeMap data structure, you may use <a href=\\\"http://www.grantjenks.com/docs/sortedcontainers/\\\" target=\\\"_blank\\\">sortedcontainers</a> library.</p>\\r\\n\\r\\n<p>Note that Python 2.7 <a href=\\\"https://www.python.org/dev/peps/pep-0373/\\\" target=\\\"_blank\\\">will not be maintained past 2020</a>. For the latest Python, please choose Python3 instead.</p>\"], \"c\": [\"C\", \"<p>Compiled with <code>gcc 8.2</code> using the gnu11 standard.</p>\\r\\n\\r\\n<p>Your code is compiled with level one optimization (<code>-O1</code>). <a href=\\\"https://github.com/google/sanitizers/wiki/AddressSanitizer\\\" target=\\\"_blank\\\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\\r\\n\\r\\n<p>Most standard library headers are already included automatically for your convenience.</p>\\r\\n\\r\\n<p>For hash table operations, you may use <a href=\\\"https://troydhanson.github.io/uthash/\\\" target=\\\"_blank\\\">uthash</a>. \\\"uthash.h\\\" is included by default. Below are some examples:</p>\\r\\n\\r\\n<p><b>1. Adding an item to a hash.</b>\\r\\n<pre>\\r\\nstruct hash_entry {\\r\\n int id; /* we'll use this field as the key */\\r\\n char name[10];\\r\\n UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n</pre>\\r\\n</p>\\r\\n\\r\\n<p><b>2. Looking up an item in a hash:</b>\\r\\n<pre>\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n struct hash_entry *s;\\r\\n HASH_FIND_INT(users, &user_id, s);\\r\\n return s;\\r\\n}\\r\\n</pre>\\r\\n</p>\\r\\n\\r\\n<p><b>3. Deleting an item in a hash:</b>\\r\\n<pre>\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n</pre>\\r\\n</p>\"], \"csharp\": [\"C#\", \"<p><a href=\\\"https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-10\\\" target=\\\"_blank\\\">C# 10 with .NET 6 runtime</a></p>\"], \"javascript\": [\"JavaScript\", \"<p><code>Node.js 16.13.2</code>.</p>\\r\\n\\r\\n<p>Your code is run with <code>--harmony</code> flag, enabling <a href=\\\"http://node.green/\\\" target=\\\"_blank\\\">new ES6 features</a>.</p>\\r\\n\\r\\n<p><a href=\\\"https://lodash.com\\\" target=\\\"_blank\\\">lodash.js</a> library is included by default.</p>\\r\\n\\r\\n<p>For Priority Queue / Queue data structures, you may use 5.3.0 version of <a href=\\\"https://github.com/datastructures-js/priority-queue/tree/fb4fdb984834421279aeb081df7af624d17c2a03\\\" target=\\\"_blank\\\">datastructures-js/priority-queue</a> and 4.2.1 version of <a href=\\\"https://githu
