{ "data": { "question": { "questionId": "26", "questionFrontendId": "26", "categoryTitle": "Algorithms", "boundTopicId": 1166, "title": "Remove Duplicates from Sorted Array", "titleSlug": "remove-duplicates-from-sorted-array", "content": "

Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same.

\n\n

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.

\n\n

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

\n\n

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

\n\n

Custom Judge:

\n\n

The judge will test your solution with the following code:

\n\n
\nint[] nums = [...]; // Input array\nint[] expectedNums = [...]; // The expected answer with correct length\n\nint k = removeDuplicates(nums); // Calls your implementation\n\nassert k == expectedNums.length;\nfor (int i = 0; i < k; i++) {\n    assert nums[i] == expectedNums[i];\n}\n
\n\n

If all assertions pass, then your solution will be accepted.

\n\n

 

\n

Example 1:

\n\n
\nInput: nums = [1,1,2]\nOutput: 2, nums = [1,2,_]\nExplanation: Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively.\nIt does not matter what you leave beyond the returned k (hence they are underscores).\n
\n\n

Example 2:

\n\n
\nInput: nums = [0,0,1,1,1,2,2,3,3,4]\nOutput: 5, nums = [0,1,2,3,4,_,_,_,_,_]\nExplanation: Your function should return k = 5, with the first five elements of nums being 0, 1, 2, 3, and 4 respectively.\nIt does not matter what you leave beyond the returned k (hence they are underscores).\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "删除有序数组中的重复项", "translatedContent": "

给你一个 升序排列 的数组 nums ，请你 原地 删除重复出现的元素，使每个元素 只出现一次 ，返回删除后数组的新长度。元素的 相对顺序 应该保持 一致 。

\n\n

由于在某些语言中不能改变数组的长度，所以必须将结果放在数组nums的第一部分。更规范地说，如果在删除重复项之后有 k 个元素，那么 nums 的前 k 个元素应该保存最终结果。

\n\n

将最终结果插入 nums 的前 k 个位置后返回 k 。

\n\n

不要使用额外的空间，你必须在 原地 修改输入数组 并在使用 O(1) 额外空间的条件下完成。

\n\n

判题标准:

\n\n

系统会用下面的代码来测试你的题解:

\n\n
\nint[] nums = [...]; // 输入数组\nint[] expectedNums = [...]; // 长度正确的期望答案\n\nint k = removeDuplicates(nums); // 调用\n\nassert k == expectedNums.length;\nfor (int i = 0; i < k; i++) {\n    assert nums[i] == expectedNums[i];\n}
\n\n

如果所有断言都通过，那么您的题解将被 通过。

\n\n

 

\n\n

示例 1：

\n\n
\n输入：nums = [1,1,2]\n输出：2, nums = [1,2,_]\n解释：函数应该返回新的长度 2 ，并且原数组 nums 的前两个元素被修改为 1, 2 。不需要考虑数组中超出新长度后面的元素。\n
\n\n

示例 2：

\n\n
\n输入：nums = [0,0,1,1,1,2,2,3,3,4]\n输出：5, nums = [0,1,2,3,4]\n解释：函数应该返回新的长度 5 ， 并且原数组 nums 的前五个元素被修改为 0, 1, 2, 3, 4 。不需要考虑数组中超出新长度后面的元素。\n
\n\n

 

\n\n

提示：

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