21 lines
495 B
Markdown
21 lines
495 B
Markdown
Given an unsorted array of integers `nums`, return _the length of the longest consecutive elements sequence._
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You must write an algorithm that runs in `O(n)` time.
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**Example 1:**
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Input: nums = [100,4,200,1,3,2]
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Output: 4
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Explanation: The longest consecutive elements sequence is [1, 2, 3, 4]. Therefore its length is 4.
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**Example 2:**
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Input: nums = [0,3,7,2,5,8,4,6,0,1]
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Output: 9
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**Constraints:**
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* `0 <= nums.length <= 105`
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* `-109 <= nums[i] <= 109` |