{ "data": { "question": { "questionId": "1270", "questionFrontendId": "1172", "boundTopicId": null, "title": "Dinner Plate Stacks", "titleSlug": "dinner-plate-stacks", "content": "

You have an infinite number of stacks arranged in a row and numbered (left to right) from 0, each of the stacks has the same maximum capacity.

\n\n

Implement the DinnerPlates class:

\n\n\n\n

 

\n

Example 1:

\n\n
\nInput\n["DinnerPlates", "push", "push", "push", "push", "push", "popAtStack", "push", "push", "popAtStack", "popAtStack", "pop", "pop", "pop", "pop", "pop"]\n[[2], [1], [2], [3], [4], [5], [0], [20], [21], [0], [2], [], [], [], [], []]\nOutput\n[null, null, null, null, null, null, 2, null, null, 20, 21, 5, 4, 3, 1, -1]\n\nExplanation: \nDinnerPlates D = DinnerPlates(2);  // Initialize with capacity = 2\nD.push(1);\nD.push(2);\nD.push(3);\nD.push(4);\nD.push(5);         // The stacks are now:  2  4\n                                           1  3  5\n                                           ﹈ ﹈ ﹈\nD.popAtStack(0);   // Returns 2.  The stacks are now:     4\n                                                       1  3  5\n                                                       ﹈ ﹈ ﹈\nD.push(20);        // The stacks are now: 20  4\n                                           1  3  5\n                                           ﹈ ﹈ ﹈\nD.push(21);        // The stacks are now: 20  4 21\n                                           1  3  5\n                                           ﹈ ﹈ ﹈\nD.popAtStack(0);   // Returns 20.  The stacks are now:     4 21\n                                                        1  3  5\n                                                        ﹈ ﹈ ﹈\nD.popAtStack(2);   // Returns 21.  The stacks are now:     4\n                                                        1  3  5\n                                                        ﹈ ﹈ ﹈ \nD.pop()            // Returns 5.  The stacks are now:      4\n                                                        1  3 \n                                                        ﹈ ﹈  \nD.pop()            // Returns 4.  The stacks are now:   1  3 \n                                                        ﹈ ﹈   \nD.pop()            // Returns 3.  The stacks are now:   1 \n                                                        ﹈   \nD.pop()            // Returns 1.  There are no stacks.\nD.pop()            // Returns -1.  There are still no stacks.\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": null, "translatedContent": null, "isPaidOnly": false, "difficulty": "Hard", "likes": 317, "dislikes": 49, "isLiked": null, "similarQuestions": "[]", "exampleTestcases": "[\"DinnerPlates\",\"push\",\"push\",\"push\",\"push\",\"push\",\"popAtStack\",\"push\",\"push\",\"popAtStack\",\"popAtStack\",\"pop\",\"pop\",\"pop\",\"pop\",\"pop\"]\n[[2],[1],[2],[3],[4],[5],[0],[20],[21],[0],[2],[],[],[],[],[]]", "categoryTitle": "Algorithms", "contributors": [], "topicTags": [ { "name": "Hash Table", "slug": "hash-table", "translatedName": null, "__typename": "TopicTagNode" }, { "name": "Stack", "slug": "stack", "translatedName": null, "__typename": "TopicTagNode" }, { "name": "Design", "slug": "design", "translatedName": null, "__typename": "TopicTagNode" }, { "name": "Heap (Priority Queue)", "slug": "heap-priority-queue", "translatedName": null, "__typename": "TopicTagNode" } ], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class DinnerPlates {\npublic:\n DinnerPlates(int capacity) {\n \n }\n \n void push(int val) {\n \n }\n \n int pop() {\n \n }\n \n int popAtStack(int index) {\n \n }\n};\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * DinnerPlates* obj = new DinnerPlates(capacity);\n * obj->push(val);\n * int param_2 = obj->pop();\n * int param_3 = obj->popAtStack(index);\n */", "__typename": "CodeSnippetNode" }, { "lang": "Java", "langSlug": "java", "code": "class DinnerPlates {\n\n public DinnerPlates(int capacity) {\n \n }\n \n public void push(int val) {\n \n }\n \n public int pop() {\n \n }\n \n public int popAtStack(int index) {\n \n }\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * DinnerPlates obj = new DinnerPlates(capacity);\n * obj.push(val);\n * int param_2 = obj.pop();\n * int param_3 = obj.popAtStack(index);\n */", "__typename": "CodeSnippetNode" }, { "lang": "Python", "langSlug": "python", "code": "class DinnerPlates(object):\n\n def __init__(self, capacity):\n \"\"\"\n :type capacity: int\n \"\"\"\n \n\n def push(self, val):\n \"\"\"\n :type val: int\n :rtype: None\n \"\"\"\n \n\n def pop(self):\n \"\"\"\n :rtype: int\n \"\"\"\n \n\n def popAtStack(self, index):\n \"\"\"\n :type index: int\n :rtype: int\n \"\"\"\n \n\n\n# Your DinnerPlates object will be instantiated and called as such:\n# obj = DinnerPlates(capacity)\n# obj.push(val)\n# param_2 = obj.pop()\n# param_3 = obj.popAtStack(index)", "__typename": "CodeSnippetNode" }, { "lang": "Python3", "langSlug": "python3", "code": "class DinnerPlates:\n\n def __init__(self, capacity: int):\n \n\n def push(self, val: int) -> None:\n \n\n def pop(self) -> int:\n \n\n def popAtStack(self, index: int) -> int:\n \n\n\n# Your DinnerPlates object will be instantiated and called as such:\n# obj = DinnerPlates(capacity)\n# obj.push(val)\n# param_2 = obj.pop()\n# param_3 = obj.popAtStack(index)", "__typename": "CodeSnippetNode" }, { "lang": "C", "langSlug": "c", "code": "\n\n\ntypedef struct {\n \n} DinnerPlates;\n\n\nDinnerPlates* dinnerPlatesCreate(int capacity) {\n \n}\n\nvoid dinnerPlatesPush(DinnerPlates* obj, int val) {\n \n}\n\nint dinnerPlatesPop(DinnerPlates* obj) {\n \n}\n\nint dinnerPlatesPopAtStack(DinnerPlates* obj, int index) {\n \n}\n\nvoid dinnerPlatesFree(DinnerPlates* obj) {\n \n}\n\n/**\n * Your DinnerPlates struct will be instantiated and called as such:\n * DinnerPlates* obj = dinnerPlatesCreate(capacity);\n * dinnerPlatesPush(obj, val);\n \n * int param_2 = dinnerPlatesPop(obj);\n \n * int param_3 = dinnerPlatesPopAtStack(obj, index);\n \n * dinnerPlatesFree(obj);\n*/", "__typename": "CodeSnippetNode" }, { "lang": "C#", "langSlug": "csharp", "code": "public class DinnerPlates {\n\n public DinnerPlates(int capacity) {\n \n }\n \n public void Push(int val) {\n \n }\n \n public int Pop() {\n \n }\n \n public int PopAtStack(int index) {\n \n }\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * DinnerPlates obj = new DinnerPlates(capacity);\n * obj.Push(val);\n * int param_2 = obj.Pop();\n * int param_3 = obj.PopAtStack(index);\n */", "__typename": "CodeSnippetNode" }, { "lang": "JavaScript", "langSlug": "javascript", "code": "/**\n * @param {number} capacity\n */\nvar DinnerPlates = function(capacity) {\n \n};\n\n/** \n * @param {number} val\n * @return {void}\n */\nDinnerPlates.prototype.push = function(val) {\n \n};\n\n/**\n * @return {number}\n */\nDinnerPlates.prototype.pop = function() {\n \n};\n\n/** \n * @param {number} index\n * @return {number}\n */\nDinnerPlates.prototype.popAtStack = function(index) {\n \n};\n\n/** \n * Your DinnerPlates object will be instantiated and called as such:\n * var obj = new DinnerPlates(capacity)\n * obj.push(val)\n * var param_2 = obj.pop()\n * var param_3 = obj.popAtStack(index)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Ruby", "langSlug": "ruby", "code": "class DinnerPlates\n\n=begin\n :type capacity: Integer\n=end\n def initialize(capacity)\n \n end\n\n\n=begin\n :type val: Integer\n :rtype: Void\n=end\n def push(val)\n \n end\n\n\n=begin\n :rtype: Integer\n=end\n def pop()\n \n end\n\n\n=begin\n :type index: Integer\n :rtype: Integer\n=end\n def pop_at_stack(index)\n \n end\n\n\nend\n\n# Your DinnerPlates object will be instantiated and called as such:\n# obj = DinnerPlates.new(capacity)\n# obj.push(val)\n# param_2 = obj.pop()\n# param_3 = obj.pop_at_stack(index)", "__typename": "CodeSnippetNode" }, { "lang": "Swift", "langSlug": "swift", "code": "\nclass DinnerPlates {\n\n init(_ capacity: Int) {\n \n }\n \n func push(_ val: Int) {\n \n }\n \n func pop() -> Int {\n \n }\n \n func popAtStack(_ index: Int) -> Int {\n \n }\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * let obj = DinnerPlates(capacity)\n * obj.push(val)\n * let ret_2: Int = obj.pop()\n * let ret_3: Int = obj.popAtStack(index)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Go", "langSlug": "golang", "code": "type DinnerPlates struct {\n \n}\n\n\nfunc Constructor(capacity int) DinnerPlates {\n \n}\n\n\nfunc (this *DinnerPlates) Push(val int) {\n \n}\n\n\nfunc (this *DinnerPlates) Pop() int {\n \n}\n\n\nfunc (this *DinnerPlates) PopAtStack(index int) int {\n \n}\n\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * obj := Constructor(capacity);\n * obj.Push(val);\n * param_2 := obj.Pop();\n * param_3 := obj.PopAtStack(index);\n */", "__typename": "CodeSnippetNode" }, { "lang": "Scala", "langSlug": "scala", "code": "class DinnerPlates(_capacity: Int) {\n\n def push(`val`: Int) {\n \n }\n\n def pop(): Int = {\n \n }\n\n def popAtStack(index: Int): Int = {\n \n }\n\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * var obj = new DinnerPlates(capacity)\n * obj.push(`val`)\n * var param_2 = obj.pop()\n * var param_3 = obj.popAtStack(index)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Kotlin", "langSlug": "kotlin", "code": "class DinnerPlates(capacity: Int) {\n\n fun push(`val`: Int) {\n \n }\n\n fun pop(): Int {\n \n }\n\n fun popAtStack(index: Int): Int {\n \n }\n\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * var obj = DinnerPlates(capacity)\n * obj.push(`val`)\n * var param_2 = obj.pop()\n * var param_3 = obj.popAtStack(index)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Rust", "langSlug": "rust", "code": "struct DinnerPlates {\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 DinnerPlates {\n\n fn new(capacity: i32) -> Self {\n \n }\n \n fn push(&self, val: i32) {\n \n }\n \n fn pop(&self) -> i32 {\n \n }\n \n fn pop_at_stack(&self, index: i32) -> i32 {\n \n }\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * let obj = DinnerPlates::new(capacity);\n * obj.push(val);\n * let ret_2: i32 = obj.pop();\n * let ret_3: i32 = obj.pop_at_stack(index);\n */", "__typename": "CodeSnippetNode" }, { "lang": "PHP", "langSlug": "php", "code": "class DinnerPlates {\n /**\n * @param Integer $capacity\n */\n function __construct($capacity) {\n \n }\n \n /**\n * @param Integer $val\n * @return NULL\n */\n function push($val) {\n \n }\n \n /**\n * @return Integer\n */\n function pop() {\n \n }\n \n /**\n * @param Integer $index\n * @return Integer\n */\n function popAtStack($index) {\n \n }\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * $obj = DinnerPlates($capacity);\n * $obj->push($val);\n * $ret_2 = $obj->pop();\n * $ret_3 = $obj->popAtStack($index);\n */", "__typename": "CodeSnippetNode" }, { "lang": "TypeScript", "langSlug": "typescript", "code": "class DinnerPlates {\n constructor(capacity: number) {\n\n }\n\n push(val: number): void {\n\n }\n\n pop(): number {\n\n }\n\n popAtStack(index: number): number {\n\n }\n}\n\n/**\n * Your DinnerPlates object will be instantiated and called as such:\n * var obj = new DinnerPlates(capacity)\n * obj.push(val)\n * var param_2 = obj.pop()\n * var param_3 = obj.popAtStack(index)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Racket", "langSlug": "racket", "code": "(define dinner-plates%\n (class object%\n (super-new)\n\n ; capacity : exact-integer?\n (init-field\n capacity)\n \n ; push : exact-integer? -> void?\n (define/public (push val)\n\n )\n ; pop : -> exact-integer?\n (define/public (pop)\n\n )\n ; pop-at-stack : exact-integer? -> exact-integer?\n (define/public (pop-at-stack index)\n\n )))\n\n;; Your dinner-plates% object will be instantiated and called as such:\n;; (define obj (new dinner-plates% [capacity capacity]))\n;; (send obj push val)\n;; (define param_2 (send obj pop))\n;; (define param_3 (send obj pop-at-stack index))", "__typename": "CodeSnippetNode" }, { "lang": "Erlang", "langSlug": "erlang", "code": "-spec dinner_plates_init_(Capacity :: integer()) -> any().\ndinner_plates_init_(Capacity) ->\n .\n\n-spec dinner_plates_push(Val :: integer()) -> any().\ndinner_plates_push(Val) ->\n .\n\n-spec dinner_plates_pop() -> integer().\ndinner_plates_pop() ->\n .\n\n-spec dinner_plates_pop_at_stack(Index :: integer()) -> integer().\ndinner_plates_pop_at_stack(Index) ->\n .\n\n\n%% Your functions will be called as such:\n%% dinner_plates_init_(Capacity),\n%% dinner_plates_push(Val),\n%% Param_2 = dinner_plates_pop(),\n%% Param_3 = dinner_plates_pop_at_stack(Index),\n\n%% dinner_plates_init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" }, { "lang": "Elixir", "langSlug": "elixir", "code": "defmodule DinnerPlates do\n @spec init_(capacity :: integer) :: any\n def init_(capacity) do\n\n end\n\n @spec push(val :: integer) :: any\n def push(val) do\n\n end\n\n @spec pop() :: integer\n def pop() do\n\n end\n\n @spec pop_at_stack(index :: integer) :: integer\n def pop_at_stack(index) do\n\n end\nend\n\n# Your functions will be called as such:\n# DinnerPlates.init_(capacity)\n# DinnerPlates.push(val)\n# param_2 = DinnerPlates.pop()\n# param_3 = DinnerPlates.pop_at_stack(index)\n\n# DinnerPlates.init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" } ], "stats": "{\"totalAccepted\": \"13.6K\", \"totalSubmission\": \"39.5K\", \"totalAcceptedRaw\": 13583, \"totalSubmissionRaw\": 39520, \"acRate\": \"34.4%\"}", "hints": [ "Use a data structure to save the plate status. You may need to operate the exact index. Maintain the leftmost vacant stack and the rightmost non-empty stack.", "Use a list of stack to store the plate status. Use heap to maintain the leftmost and rightmost valid stack." ], "solution": null, "status": null, "sampleTestCase": "[\"DinnerPlates\",\"push\",\"push\",\"push\",\"push\",\"push\",\"popAtStack\",\"push\",\"push\",\"popAtStack\",\"popAtStack\",\"pop\",\"pop\",\"pop\",\"pop\",\"pop\"]\n[[2],[1],[2],[3],[4],[5],[0],[20],[21],[0],[2],[],[],[],[],[]]", "metaData": "{\n \"classname\": \"DinnerPlates\",\n \"constructor\": {\n \"params\": [\n {\n \"type\": \"integer\",\n \"name\": \"capacity\"\n }\n ]\n },\n \"methods\": [\n {\n \"params\": [\n {\n \"type\": \"integer\",\n \"name\": \"val\"\n }\n ],\n \"name\": \"push\",\n \"return\": {\n \"type\": \"void\"\n }\n },\n {\n \"params\": [],\n \"name\": \"pop\",\n \"return\": {\n \"type\": \"integer\"\n }\n },\n {\n \"params\": [\n {\n \"type\": \"integer\",\n \"name\": \"index\"\n }\n ],\n \"return\": {\n \"type\": \"integer\"\n },\n \"name\": \"popAtStack\"\n }\n ],\n \"return\": {\n \"type\": \"boolean\"\n },\n \"systemdesign\": true\n}", "judgerAvailable": true, "judgeType": "large", "mysqlSchemas": [], "enableRunCode": true, "enableTestMode": false, "enableDebugger": true, "envInfo": "{\"cpp\": [\"C++\", \"

Compiled with clang 11 using the latest C++ 17 standard.

\\r\\n\\r\\n

Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.

\\r\\n\\r\\n

Most standard library headers are already included automatically for your convenience.

\"], \"java\": [\"Java\", \"

OpenJDK 17 . Java 8 features such as lambda expressions and stream API can be used.

\\r\\n\\r\\n

Most standard library headers are already included automatically for your convenience.

\\r\\n

Includes Pair class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.

\"], \"python\": [\"Python\", \"

Python 2.7.12.

\\r\\n\\r\\n

Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.

\\r\\n\\r\\n

For Map/TreeMap data structure, you may use sortedcontainers library.

\\r\\n\\r\\n

Note that Python 2.7 will not be maintained past 2020. For the latest Python, please choose Python3 instead.

\"], \"c\": [\"C\", \"

Compiled with gcc 8.2 using the gnu99 standard.

\\r\\n\\r\\n

Your code is compiled with level one optimization (-O1). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.

\\r\\n\\r\\n

Most standard library headers are already included automatically for your convenience.

\\r\\n\\r\\n

For hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:

\\r\\n\\r\\n

1. Adding an item to a hash.\\r\\n

\\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
\\r\\n

\\r\\n\\r\\n

2. Looking up an item in a hash:\\r\\n

\\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
\\r\\n

\\r\\n\\r\\n

3. Deleting an item in a hash:\\r\\n

\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n    HASH_DEL(users, user);  \\r\\n}\\r\\n
\\r\\n

\"], \"csharp\": [\"C#\", \"

C# 10 with .NET 6 runtime

\\r\\n\\r\\n

Your code is compiled with debug flag enabled (/debug).

\"], \"javascript\": [\"JavaScript\", \"

Node.js 16.13.2.

\\r\\n\\r\\n

Your code is run with --harmony flag, enabling new ES6 features.

\\r\\n\\r\\n

lodash.js library is included by default.

\\r\\n\\r\\n

For Priority Queue / Queue data structures, you may use datastructures-js/priority-queue and datastructures-js/queue.

\"], \"ruby\": [\"Ruby\", \"

Ruby 3.1

\\r\\n\\r\\n

Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms

\"], \"swift\": [\"Swift\", \"

Swift 5.5.2.

\"], \"golang\": [\"Go\", \"

Go 1.17.6.

\\r\\n\\r\\n

Support https://godoc.org/github.com/emirpasic/gods library.

\"], \"python3\": [\"Python3\", \"

Python 3.10.

\\r\\n\\r\\n

Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.

\\r\\n\\r\\n

For Map/TreeMap data structure, you may use sortedcontainers library.

\"], \"scala\": [\"Scala\", \"

Scala 2.13.7.

\"], \"kotlin\": [\"Kotlin\", \"

Kotlin 1.3.10.

\"], \"rust\": [\"Rust\", \"

Rust 1.58.1

\\r\\n\\r\\n

Supports rand v0.6\\u00a0from crates.io

\"], \"php\": [\"PHP\", \"

PHP 8.1.

\\r\\n

With bcmath module

\"], \"typescript\": [\"Typescript\", \"

TypeScript 4.5.4, Node.js 16.13.2.

\\r\\n\\r\\n

Your code is run with --harmony flag, enabling new ES2020 features.

\\r\\n\\r\\n

lodash.js library is included by default.

\"], \"racket\": [\"Racket\", \"

Run with Racket 8.3.

\"], \"erlang\": [\"Erlang\", \"Erlang/OTP 24.2\"], \"elixir\": [\"Elixir\", \"Elixir 1.13.0 with Erlang/OTP 24.2\"]}", "libraryUrl": null, "adminUrl": null, "challengeQuestion": null, "__typename": "QuestionNode" } } }