{ "data": { "question": { "questionId": "27", "questionFrontendId": "27", "boundTopicId": null, "title": "Remove Element", "titleSlug": "remove-element", "content": "

Given an integer array nums and an integer val, remove all occurrences of val in nums in-place. The relative order of the elements may be changed.

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Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements.

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Return k after placing the final result in the first k slots of nums.

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Do not allocate extra space for another array. You must do this by modifying the input array in-place with O(1) extra memory.

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Custom Judge:

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The judge will test your solution with the following code:

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\nint[] nums = [...]; // Input array\nint val = ...; // Value to remove\nint[] expectedNums = [...]; // The expected answer with correct length.\n                            // It is sorted with no values equaling val.\n\nint k = removeElement(nums, val); // Calls your implementation\n\nassert k == expectedNums.length;\nsort(nums, 0, k); // Sort the first k elements of nums\nfor (int i = 0; i < actualLength; i++) {\n    assert nums[i] == expectedNums[i];\n}\n
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If all assertions pass, then your solution will be accepted.

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Example 1:

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\nInput: nums = [3,2,2,3], val = 3\nOutput: 2, nums = [2,2,_,_]\nExplanation: Your function should return k = 2, with the first two elements of nums being 2.\nIt does not matter what you leave beyond the returned k (hence they are underscores).\n
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Example 2:

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\nInput: nums = [0,1,2,2,3,0,4,2], val = 2\nOutput: 5, nums = [0,1,4,0,3,_,_,_]\nExplanation: Your function should return k = 5, with the first five elements of nums containing 0, 0, 1, 3, and 4.\nNote that the five elements can be returned in any order.\nIt does not matter what you leave beyond the returned k (hence they are underscores).\n
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Constraints:

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", "Yet another direction of thought is to consider the elements to be removed as non-existent. In a single pass, if we keep copying the visible elements in-place, that should also solve this problem for us." ], "solution": { "id": "22", "canSeeDetail": true, "paidOnly": false, "hasVideoSolution": false, "paidOnlyVideo": true, "__typename": "ArticleNode" }, "status": null, "sampleTestCase": "[3,2,2,3]\n3", "metaData": "{\r\n \"name\": \"removeElement\",\r\n \"params\": [\r\n {\r\n \"name\": \"nums\",\r\n \"type\": \"integer[]\"\r\n },\r\n {\r\n \"name\": \"val\",\r\n \"type\": \"integer\"\r\n }\r\n ],\r\n \"return\": {\r\n \"type\": \"integer\"\r\n },\r\n \"output\": {\r\n \"paramindex\": 0,\r\n \"size\": \"ret\"\r\n }\r\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.

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

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

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

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

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

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Python 2.7.12.

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

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

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

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Compiled with gcc 8.2 using the gnu99 standard.

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

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

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

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

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\\r\\n

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

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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
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C# 10 with .NET 6 runtime

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

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Node.js 16.13.2.

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

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

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Ruby 3.1

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

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Swift 5.5.2.

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Go 1.17.6.

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Python 3.10.

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

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

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Scala 2.13.7.

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Kotlin 1.3.10.

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Rust 1.58.1

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PHP 8.1.

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With bcmath module

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TypeScript 4.5.4, Node.js 16.13.2.

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Run with Racket 8.3.

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