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54 lines
2.7 KiB
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54 lines
2.7 KiB
HTML
<p>Given an integer array <code>nums</code> sorted in <strong>non-decreasing order</strong>, remove the duplicates <a href="https://en.wikipedia.org/wiki/In-place_algorithm" target="_blank"><strong>in-place</strong></a> such that each unique element appears only <strong>once</strong>. The <strong>relative order</strong> of the elements should be kept the <strong>same</strong>.</p>
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<p>Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the <strong>first part</strong> of the array <code>nums</code>. More formally, if there are <code>k</code> elements after removing the duplicates, then the first <code>k</code> elements of <code>nums</code> should hold the final result. It does not matter what you leave beyond the first <code>k</code> elements.</p>
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<p>Return <code>k</code><em> after placing the final result in the first </em><code>k</code><em> slots of </em><code>nums</code>.</p>
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<p>Do <strong>not</strong> allocate extra space for another array. You must do this by <strong>modifying the input array <a href="https://en.wikipedia.org/wiki/In-place_algorithm" target="_blank">in-place</a></strong> with O(1) extra memory.</p>
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<p><strong>Custom Judge:</strong></p>
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<p>The judge will test your solution with the following code:</p>
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<pre>
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int[] nums = [...]; // Input array
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int[] expectedNums = [...]; // The expected answer with correct length
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int k = removeDuplicates(nums); // Calls your implementation
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assert k == expectedNums.length;
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for (int i = 0; i < k; i++) {
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assert nums[i] == expectedNums[i];
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}
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</pre>
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<p>If all assertions pass, then your solution will be <strong>accepted</strong>.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> nums = [1,1,2]
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<strong>Output:</strong> 2, nums = [1,2,_]
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<strong>Explanation:</strong> Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively.
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It does not matter what you leave beyond the returned k (hence they are underscores).
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> nums = [0,0,1,1,1,2,2,3,3,4]
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<strong>Output:</strong> 5, nums = [0,1,2,3,4,_,_,_,_,_]
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<strong>Explanation:</strong> Your function should return k = 5, with the first five elements of nums being 0, 1, 2, 3, and 4 respectively.
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It does not matter what you leave beyond the returned k (hence they are underscores).
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= nums.length <= 3 * 10<sup>4</sup></code></li>
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<li><code>-100 <= nums[i] <= 100</code></li>
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<li><code>nums</code> is sorted in <strong>non-decreasing</strong> order.</li>
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</ul>
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