{ "data": { "question": { "questionId": "1767", "questionFrontendId": "1670", "categoryTitle": "Algorithms", "boundTopicId": 499831, "title": "Design Front Middle Back Queue", "titleSlug": "design-front-middle-back-queue", "content": "

Design a queue that supports push and pop operations in the front, middle, and back.

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Implement the FrontMiddleBack class:

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Notice that when there are two middle position choices, the operation is performed on the frontmost middle position choice. For example:

\n\n\n\n

 

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Example 1:

\n\n
\nInput:\n["FrontMiddleBackQueue", "pushFront", "pushBack", "pushMiddle", "pushMiddle", "popFront", "popMiddle", "popMiddle", "popBack", "popFront"]\n[[], [1], [2], [3], [4], [], [], [], [], []]\nOutput:\n[null, null, null, null, null, 1, 3, 4, 2, -1]\n\nExplanation:\nFrontMiddleBackQueue q = new FrontMiddleBackQueue();\nq.pushFront(1);   // [1]\nq.pushBack(2);    // [1, 2]\nq.pushMiddle(3);  // [1, 3, 2]\nq.pushMiddle(4);  // [1, 4, 3, 2]\nq.popFront();     // return 1 -> [4, 3, 2]\nq.popMiddle();    // return 3 -> [4, 2]\nq.popMiddle();    // return 4 -> [2]\nq.popBack();      // return 2 -> []\nq.popFront();     // return -1 -> [] (The queue is empty)\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "设计前中后队列", "translatedContent": "

请你设计一个队列，支持在前，中，后三个位置的 push 和 pop 操作。

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请你完成 FrontMiddleBack 类：

\n\n\n\n

请注意当有 两个 中间位置的时候，选择靠前面的位置进行操作。比方说：

\n\n\n\n

 

\n\n

示例 1：

\n\n
\n输入：\n[\"FrontMiddleBackQueue\", \"pushFront\", \"pushBack\", \"pushMiddle\", \"pushMiddle\", \"popFront\", \"popMiddle\", \"popMiddle\", \"popBack\", \"popFront\"]\n[[], [1], [2], [3], [4], [], [], [], [], []]\n输出：\n[null, null, null, null, null, 1, 3, 4, 2, -1]\n\n解释：\nFrontMiddleBackQueue q = new FrontMiddleBackQueue();\nq.pushFront(1);   // [1]\nq.pushBack(2);    // [1, 2]\nq.pushMiddle(3);  // [1, 3, 2]\nq.pushMiddle(4);  // [1, 4, 3, 2]\nq.popFront();     // 返回 1 -> [4, 3, 2]\nq.popMiddle();    // 返回 3 -> [4, 2]\nq.popMiddle();    // 返回 4 -> [2]\nq.popBack();      // 返回 2 -> []\nq.popFront();     // 返回 -1 -> [] （队列为空）\n
\n\n

 

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提示：

\n\n\n", "isPaidOnly": false, "difficulty": "Medium", "likes": 106, "dislikes": 0, "isLiked": null, "similarQuestions": "[{\"title\": \"Design Circular Deque\", \"titleSlug\": \"design-circular-deque\", \"difficulty\": \"Medium\", \"translatedTitle\": \"\\u8bbe\\u8ba1\\u5faa\\u73af\\u53cc\\u7aef\\u961f\\u5217\", \"isPaidOnly\": false}, {\"title\": \"Design Circular Queue\", \"titleSlug\": \"design-circular-queue\", \"difficulty\": \"Medium\", \"translatedTitle\": \"\\u8bbe\\u8ba1\\u5faa\\u73af\\u961f\\u5217\", \"isPaidOnly\": false}]", "contributors": [], "langToValidPlayground": "{\"cpp\": false, \"java\": false, \"python3\": false, \"python\": false, \"javascript\": false, \"typescript\": false, \"csharp\": false, \"c\": false, \"golang\": false, \"kotlin\": false, \"swift\": false, \"rust\": false, \"ruby\": false, \"php\": false, \"dart\": false, \"scala\": false, \"elixir\": false, \"erlang\": false, \"racket\": false, \"cangjie\": false, \"bash\": false, \"html\": false, \"pythonml\": false, \"react\": false, \"vanillajs\": false, \"mysql\": false, \"mssql\": false, \"postgresql\": false, \"oraclesql\": false, \"pythondata\": false}", "topicTags": [ { "name": "Design", "slug": "design", "translatedName": "设计", "__typename": "TopicTagNode" }, { "name": "Queue", "slug": "queue", "translatedName": "队列", "__typename": "TopicTagNode" }, { "name": "Array", "slug": "array", "translatedName": "数组", "__typename": "TopicTagNode" }, { "name": "Linked List", "slug": "linked-list", "translatedName": "链表", "__typename": "TopicTagNode" }, { "name": "Data Stream", "slug": "data-stream", "translatedName": "数据流", "__typename": "TopicTagNode" } ], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class FrontMiddleBackQueue {\npublic:\n FrontMiddleBackQueue() {\n \n }\n \n void pushFront(int val) {\n \n }\n \n void pushMiddle(int val) {\n \n }\n \n void pushBack(int val) {\n \n }\n \n int popFront() {\n \n }\n \n int popMiddle() {\n \n }\n \n int popBack() {\n \n }\n};\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * FrontMiddleBackQueue* obj = new FrontMiddleBackQueue();\n * obj->pushFront(val);\n * obj->pushMiddle(val);\n * obj->pushBack(val);\n * int param_4 = obj->popFront();\n * int param_5 = obj->popMiddle();\n * int param_6 = obj->popBack();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Java", "langSlug": "java", "code": "class FrontMiddleBackQueue {\n\n public FrontMiddleBackQueue() {\n \n }\n \n public void pushFront(int val) {\n \n }\n \n public void pushMiddle(int val) {\n \n }\n \n public void pushBack(int val) {\n \n }\n \n public int popFront() {\n \n }\n \n public int popMiddle() {\n \n }\n \n public int popBack() {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * FrontMiddleBackQueue obj = new FrontMiddleBackQueue();\n * obj.pushFront(val);\n * obj.pushMiddle(val);\n * obj.pushBack(val);\n * int param_4 = obj.popFront();\n * int param_5 = obj.popMiddle();\n * int param_6 = obj.popBack();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Python3", "langSlug": "python3", "code": "class FrontMiddleBackQueue:\n\n def __init__(self):\n \n\n def pushFront(self, val: int) -> None:\n \n\n def pushMiddle(self, val: int) -> None:\n \n\n def pushBack(self, val: int) -> None:\n \n\n def popFront(self) -> int:\n \n\n def popMiddle(self) -> int:\n \n\n def popBack(self) -> int:\n \n\n\n# Your FrontMiddleBackQueue object will be instantiated and called as such:\n# obj = FrontMiddleBackQueue()\n# obj.pushFront(val)\n# obj.pushMiddle(val)\n# obj.pushBack(val)\n# param_4 = obj.popFront()\n# param_5 = obj.popMiddle()\n# param_6 = obj.popBack()", "__typename": "CodeSnippetNode" }, { "lang": "Python", "langSlug": "python", "code": "class FrontMiddleBackQueue(object):\n\n def __init__(self):\n \n\n def pushFront(self, val):\n \"\"\"\n :type val: int\n :rtype: None\n \"\"\"\n \n\n def pushMiddle(self, val):\n \"\"\"\n :type val: int\n :rtype: None\n \"\"\"\n \n\n def pushBack(self, val):\n \"\"\"\n :type val: int\n :rtype: None\n \"\"\"\n \n\n def popFront(self):\n \"\"\"\n :rtype: int\n \"\"\"\n \n\n def popMiddle(self):\n \"\"\"\n :rtype: int\n \"\"\"\n \n\n def popBack(self):\n \"\"\"\n :rtype: int\n \"\"\"\n \n\n\n# Your FrontMiddleBackQueue object will be instantiated and called as such:\n# obj = FrontMiddleBackQueue()\n# obj.pushFront(val)\n# obj.pushMiddle(val)\n# obj.pushBack(val)\n# param_4 = obj.popFront()\n# param_5 = obj.popMiddle()\n# param_6 = obj.popBack()", "__typename": "CodeSnippetNode" }, { "lang": "JavaScript", "langSlug": "javascript", "code": "\nvar FrontMiddleBackQueue = function() {\n \n};\n\n/** \n * @param {number} val\n * @return {void}\n */\nFrontMiddleBackQueue.prototype.pushFront = function(val) {\n \n};\n\n/** \n * @param {number} val\n * @return {void}\n */\nFrontMiddleBackQueue.prototype.pushMiddle = function(val) {\n \n};\n\n/** \n * @param {number} val\n * @return {void}\n */\nFrontMiddleBackQueue.prototype.pushBack = function(val) {\n \n};\n\n/**\n * @return {number}\n */\nFrontMiddleBackQueue.prototype.popFront = function() {\n \n};\n\n/**\n * @return {number}\n */\nFrontMiddleBackQueue.prototype.popMiddle = function() {\n \n};\n\n/**\n * @return {number}\n */\nFrontMiddleBackQueue.prototype.popBack = function() {\n \n};\n\n/** \n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * var obj = new FrontMiddleBackQueue()\n * obj.pushFront(val)\n * obj.pushMiddle(val)\n * obj.pushBack(val)\n * var param_4 = obj.popFront()\n * var param_5 = obj.popMiddle()\n * var param_6 = obj.popBack()\n */", "__typename": "CodeSnippetNode" }, { "lang": "TypeScript", "langSlug": "typescript", "code": "class FrontMiddleBackQueue {\n constructor() {\n \n }\n\n pushFront(val: number): void {\n \n }\n\n pushMiddle(val: number): void {\n \n }\n\n pushBack(val: number): void {\n \n }\n\n popFront(): number {\n \n }\n\n popMiddle(): number {\n \n }\n\n popBack(): number {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * var obj = new FrontMiddleBackQueue()\n * obj.pushFront(val)\n * obj.pushMiddle(val)\n * obj.pushBack(val)\n * var param_4 = obj.popFront()\n * var param_5 = obj.popMiddle()\n * var param_6 = obj.popBack()\n */", "__typename": "CodeSnippetNode" }, { "lang": "C#", "langSlug": "csharp", "code": "public class FrontMiddleBackQueue {\n\n public FrontMiddleBackQueue() {\n \n }\n \n public void PushFront(int val) {\n \n }\n \n public void PushMiddle(int val) {\n \n }\n \n public void PushBack(int val) {\n \n }\n \n public int PopFront() {\n \n }\n \n public int PopMiddle() {\n \n }\n \n public int PopBack() {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * FrontMiddleBackQueue obj = new FrontMiddleBackQueue();\n * obj.PushFront(val);\n * obj.PushMiddle(val);\n * obj.PushBack(val);\n * int param_4 = obj.PopFront();\n * int param_5 = obj.PopMiddle();\n * int param_6 = obj.PopBack();\n */", "__typename": "CodeSnippetNode" }, { "lang": "C", "langSlug": "c", "code": "\n\n\ntypedef struct {\n \n} FrontMiddleBackQueue;\n\n\nFrontMiddleBackQueue* frontMiddleBackQueueCreate() {\n \n}\n\nvoid frontMiddleBackQueuePushFront(FrontMiddleBackQueue* obj, int val) {\n \n}\n\nvoid frontMiddleBackQueuePushMiddle(FrontMiddleBackQueue* obj, int val) {\n \n}\n\nvoid frontMiddleBackQueuePushBack(FrontMiddleBackQueue* obj, int val) {\n \n}\n\nint frontMiddleBackQueuePopFront(FrontMiddleBackQueue* obj) {\n \n}\n\nint frontMiddleBackQueuePopMiddle(FrontMiddleBackQueue* obj) {\n \n}\n\nint frontMiddleBackQueuePopBack(FrontMiddleBackQueue* obj) {\n \n}\n\nvoid frontMiddleBackQueueFree(FrontMiddleBackQueue* obj) {\n \n}\n\n/**\n * Your FrontMiddleBackQueue struct will be instantiated and called as such:\n * FrontMiddleBackQueue* obj = frontMiddleBackQueueCreate();\n * frontMiddleBackQueuePushFront(obj, val);\n \n * frontMiddleBackQueuePushMiddle(obj, val);\n \n * frontMiddleBackQueuePushBack(obj, val);\n \n * int param_4 = frontMiddleBackQueuePopFront(obj);\n \n * int param_5 = frontMiddleBackQueuePopMiddle(obj);\n \n * int param_6 = frontMiddleBackQueuePopBack(obj);\n \n * frontMiddleBackQueueFree(obj);\n*/", "__typename": "CodeSnippetNode" }, { "lang": "Go", "langSlug": "golang", "code": "type FrontMiddleBackQueue struct {\n \n}\n\n\nfunc Constructor() FrontMiddleBackQueue {\n \n}\n\n\nfunc (this *FrontMiddleBackQueue) PushFront(val int) {\n \n}\n\n\nfunc (this *FrontMiddleBackQueue) PushMiddle(val int) {\n \n}\n\n\nfunc (this *FrontMiddleBackQueue) PushBack(val int) {\n \n}\n\n\nfunc (this *FrontMiddleBackQueue) PopFront() int {\n \n}\n\n\nfunc (this *FrontMiddleBackQueue) PopMiddle() int {\n \n}\n\n\nfunc (this *FrontMiddleBackQueue) PopBack() int {\n \n}\n\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * obj := Constructor();\n * obj.PushFront(val);\n * obj.PushMiddle(val);\n * obj.PushBack(val);\n * param_4 := obj.PopFront();\n * param_5 := obj.PopMiddle();\n * param_6 := obj.PopBack();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Kotlin", "langSlug": "kotlin", "code": "class FrontMiddleBackQueue() {\n\n fun pushFront(`val`: Int) {\n \n }\n\n fun pushMiddle(`val`: Int) {\n \n }\n\n fun pushBack(`val`: Int) {\n \n }\n\n fun popFront(): Int {\n \n }\n\n fun popMiddle(): Int {\n \n }\n\n fun popBack(): Int {\n \n }\n\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * var obj = FrontMiddleBackQueue()\n * obj.pushFront(`val`)\n * obj.pushMiddle(`val`)\n * obj.pushBack(`val`)\n * var param_4 = obj.popFront()\n * var param_5 = obj.popMiddle()\n * var param_6 = obj.popBack()\n */", "__typename": "CodeSnippetNode" }, { "lang": "Swift", "langSlug": "swift", "code": "\nclass FrontMiddleBackQueue {\n\n init() {\n \n }\n \n func pushFront(_ val: Int) {\n \n }\n \n func pushMiddle(_ val: Int) {\n \n }\n \n func pushBack(_ val: Int) {\n \n }\n \n func popFront() -> Int {\n \n }\n \n func popMiddle() -> Int {\n \n }\n \n func popBack() -> Int {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * let obj = FrontMiddleBackQueue()\n * obj.pushFront(val)\n * obj.pushMiddle(val)\n * obj.pushBack(val)\n * let ret_4: Int = obj.popFront()\n * let ret_5: Int = obj.popMiddle()\n * let ret_6: Int = obj.popBack()\n */", "__typename": "CodeSnippetNode" }, { "lang": "Rust", "langSlug": "rust", "code": "struct FrontMiddleBackQueue {\n\n}\n\n\n/** \n * `&self` means the method takes an immutable reference.\n * If you need a mutable reference, change it to `&mut self` instead.\n */\nimpl FrontMiddleBackQueue {\n\n fn new() -> Self {\n \n }\n \n fn push_front(&self, val: i32) {\n \n }\n \n fn push_middle(&self, val: i32) {\n \n }\n \n fn push_back(&self, val: i32) {\n \n }\n \n fn pop_front(&self) -> i32 {\n \n }\n \n fn pop_middle(&self) -> i32 {\n \n }\n \n fn pop_back(&self) -> i32 {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * let obj = FrontMiddleBackQueue::new();\n * obj.push_front(val);\n * obj.push_middle(val);\n * obj.push_back(val);\n * let ret_4: i32 = obj.pop_front();\n * let ret_5: i32 = obj.pop_middle();\n * let ret_6: i32 = obj.pop_back();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Ruby", "langSlug": "ruby", "code": "class FrontMiddleBackQueue\n def initialize()\n \n end\n\n\n=begin\n :type val: Integer\n :rtype: Void\n=end\n def push_front(val)\n \n end\n\n\n=begin\n :type val: Integer\n :rtype: Void\n=end\n def push_middle(val)\n \n end\n\n\n=begin\n :type val: Integer\n :rtype: Void\n=end\n def push_back(val)\n \n end\n\n\n=begin\n :rtype: Integer\n=end\n def pop_front()\n \n end\n\n\n=begin\n :rtype: Integer\n=end\n def pop_middle()\n \n end\n\n\n=begin\n :rtype: Integer\n=end\n def pop_back()\n \n end\n\n\nend\n\n# Your FrontMiddleBackQueue object will be instantiated and called as such:\n# obj = FrontMiddleBackQueue.new()\n# obj.push_front(val)\n# obj.push_middle(val)\n# obj.push_back(val)\n# param_4 = obj.pop_front()\n# param_5 = obj.pop_middle()\n# param_6 = obj.pop_back()", "__typename": "CodeSnippetNode" }, { "lang": "PHP", "langSlug": "php", "code": "class FrontMiddleBackQueue {\n /**\n */\n function __construct() {\n \n }\n \n /**\n * @param Integer $val\n * @return NULL\n */\n function pushFront($val) {\n \n }\n \n /**\n * @param Integer $val\n * @return NULL\n */\n function pushMiddle($val) {\n \n }\n \n /**\n * @param Integer $val\n * @return NULL\n */\n function pushBack($val) {\n \n }\n \n /**\n * @return Integer\n */\n function popFront() {\n \n }\n \n /**\n * @return Integer\n */\n function popMiddle() {\n \n }\n \n /**\n * @return Integer\n */\n function popBack() {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * $obj = FrontMiddleBackQueue();\n * $obj->pushFront($val);\n * $obj->pushMiddle($val);\n * $obj->pushBack($val);\n * $ret_4 = $obj->popFront();\n * $ret_5 = $obj->popMiddle();\n * $ret_6 = $obj->popBack();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Dart", "langSlug": "dart", "code": "class FrontMiddleBackQueue {\n\n FrontMiddleBackQueue() {\n \n }\n \n void pushFront(int val) {\n \n }\n \n void pushMiddle(int val) {\n \n }\n \n void pushBack(int val) {\n \n }\n \n int popFront() {\n \n }\n \n int popMiddle() {\n \n }\n \n int popBack() {\n \n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * FrontMiddleBackQueue obj = FrontMiddleBackQueue();\n * obj.pushFront(val);\n * obj.pushMiddle(val);\n * obj.pushBack(val);\n * int param4 = obj.popFront();\n * int param5 = obj.popMiddle();\n * int param6 = obj.popBack();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Scala", "langSlug": "scala", "code": "class FrontMiddleBackQueue() {\n\n def pushFront(`val`: Int): Unit = {\n \n }\n\n def pushMiddle(`val`: Int): Unit = {\n \n }\n\n def pushBack(`val`: Int): Unit = {\n \n }\n\n def popFront(): Int = {\n \n }\n\n def popMiddle(): Int = {\n \n }\n\n def popBack(): Int = {\n \n }\n\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * val obj = new FrontMiddleBackQueue()\n * obj.pushFront(`val`)\n * obj.pushMiddle(`val`)\n * obj.pushBack(`val`)\n * val param_4 = obj.popFront()\n * val param_5 = obj.popMiddle()\n * val param_6 = obj.popBack()\n */", "__typename": "CodeSnippetNode" }, { "lang": "Elixir", "langSlug": "elixir", "code": "defmodule FrontMiddleBackQueue do\n @spec init_() :: any\n def init_() do\n \n end\n\n @spec push_front(val :: integer) :: any\n def push_front(val) do\n \n end\n\n @spec push_middle(val :: integer) :: any\n def push_middle(val) do\n \n end\n\n @spec push_back(val :: integer) :: any\n def push_back(val) do\n \n end\n\n @spec pop_front() :: integer\n def pop_front() do\n \n end\n\n @spec pop_middle() :: integer\n def pop_middle() do\n \n end\n\n @spec pop_back() :: integer\n def pop_back() do\n \n end\nend\n\n# Your functions will be called as such:\n# FrontMiddleBackQueue.init_()\n# FrontMiddleBackQueue.push_front(val)\n# FrontMiddleBackQueue.push_middle(val)\n# FrontMiddleBackQueue.push_back(val)\n# param_4 = FrontMiddleBackQueue.pop_front()\n# param_5 = FrontMiddleBackQueue.pop_middle()\n# param_6 = FrontMiddleBackQueue.pop_back()\n\n# FrontMiddleBackQueue.init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" }, { "lang": "Erlang", "langSlug": "erlang", "code": "-spec front_middle_back_queue_init_() -> any().\nfront_middle_back_queue_init_() ->\n .\n\n-spec front_middle_back_queue_push_front(Val :: integer()) -> any().\nfront_middle_back_queue_push_front(Val) ->\n .\n\n-spec front_middle_back_queue_push_middle(Val :: integer()) -> any().\nfront_middle_back_queue_push_middle(Val) ->\n .\n\n-spec front_middle_back_queue_push_back(Val :: integer()) -> any().\nfront_middle_back_queue_push_back(Val) ->\n .\n\n-spec front_middle_back_queue_pop_front() -> integer().\nfront_middle_back_queue_pop_front() ->\n .\n\n-spec front_middle_back_queue_pop_middle() -> integer().\nfront_middle_back_queue_pop_middle() ->\n .\n\n-spec front_middle_back_queue_pop_back() -> integer().\nfront_middle_back_queue_pop_back() ->\n .\n\n\n%% Your functions will be called as such:\n%% front_middle_back_queue_init_(),\n%% front_middle_back_queue_push_front(Val),\n%% front_middle_back_queue_push_middle(Val),\n%% front_middle_back_queue_push_back(Val),\n%% Param_4 = front_middle_back_queue_pop_front(),\n%% Param_5 = front_middle_back_queue_pop_middle(),\n%% Param_6 = front_middle_back_queue_pop_back(),\n\n%% front_middle_back_queue_init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" }, { "lang": "Racket", "langSlug": "racket", "code": "(define front-middle-back-queue%\n (class object%\n (super-new)\n \n (init-field)\n \n ; push-front : exact-integer? -> void?\n (define/public (push-front val)\n )\n ; push-middle : exact-integer? -> void?\n (define/public (push-middle val)\n )\n ; push-back : exact-integer? -> void?\n (define/public (push-back val)\n )\n ; pop-front : -> exact-integer?\n (define/public (pop-front)\n )\n ; pop-middle : -> exact-integer?\n (define/public (pop-middle)\n )\n ; pop-back : -> exact-integer?\n (define/public (pop-back)\n )))\n\n;; Your front-middle-back-queue% object will be instantiated and called as such:\n;; (define obj (new front-middle-back-queue%))\n;; (send obj push-front val)\n;; (send obj push-middle val)\n;; (send obj push-back val)\n;; (define param_4 (send obj pop-front))\n;; (define param_5 (send obj pop-middle))\n;; (define param_6 (send obj pop-back))", "__typename": "CodeSnippetNode" }, { "lang": "Cangjie", "langSlug": "cangjie", "code": "class FrontMiddleBackQueue {\n init() {\n\n }\n \n func pushFront(val: Int64): Unit {\n\n }\n \n func pushMiddle(val: Int64): Unit {\n\n }\n \n func pushBack(val: Int64): Unit {\n\n }\n \n func popFront(): Int64 {\n\n }\n \n func popMiddle(): Int64 {\n\n }\n \n func popBack(): Int64 {\n\n }\n}\n\n/**\n * Your FrontMiddleBackQueue object will be instantiated and called as such:\n * let obj: FrontMiddleBackQueue = FrontMiddleBackQueue()\n * obj.pushFront(val)\n * obj.pushMiddle(val)\n * obj.pushBack(val)\n * let param_4 = obj.popFront()\n * let param_5 = obj.popMiddle()\n * let param_6 = obj.popBack()\n */", "__typename": "CodeSnippetNode" } ], "stats": "{\"totalAccepted\": \"26.7K\", \"totalSubmission\": \"44.4K\", \"totalAcceptedRaw\": 26724, \"totalSubmissionRaw\": 44353, \"acRate\": \"60.3%\"}", "hints": [ "The constraints are low enough for a brute force, single array approach.", "For an O(1) per method approach, use 2 double-ended queues: one for the first half and one for the second half." ], "solution": null, "status": null, "sampleTestCase": "[\"FrontMiddleBackQueue\",\"pushFront\",\"pushBack\",\"pushMiddle\",\"pushMiddle\",\"popFront\",\"popMiddle\",\"popMiddle\",\"popBack\",\"popFront\"]\n[[],[1],[2],[3],[4],[],[],[],[],[]]", "metaData": "{\n \"classname\": \"FrontMiddleBackQueue\",\n \"constructor\": {\n \"params\": []\n },\n \"methods\": [\n {\n \"params\": [\n {\n \"type\": \"integer\",\n \"name\": \"val\"\n }\n ],\n \"name\": \"pushFront\",\n \"return\": {\n \"type\": \"void\"\n }\n },\n {\n \"params\": [\n {\n \"type\": \"integer\",\n \"name\": \"val\"\n }\n ],\n \"name\": \"pushMiddle\",\n \"return\": {\n \"type\": \"void\"\n }\n },\n {\n \"params\": [\n {\n \"type\": \"integer\",\n \"name\": \"val\"\n }\n ],\n \"name\": \"pushBack\",\n \"return\": {\n \"type\": \"void\"\n }\n },\n {\n \"params\": [],\n \"name\": \"popFront\",\n \"return\": {\n \"type\": \"integer\"\n }\n },\n {\n \"params\": [],\n \"name\": \"popMiddle\",\n \"return\": {\n \"type\": \"integer\"\n }\n },\n {\n \"params\": [],\n \"name\": \"popBack\",\n \"return\": {\n \"type\": \"integer\"\n }\n }\n ],\n \"return\": {\n \"type\": \"boolean\"\n },\n \"systemdesign\": true\n}", "judgerAvailable": true, "judgeType": "large", "mysqlSchemas": [], "enableRunCode": true, "envInfo": "{\"cpp\":[\"C++\",\"

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}