<p>Given an unsorted array of integers <code>nums</code>, return <em>the length of the longest consecutive elements sequence.</em></p>

<p>You must write an algorithm that runs in&nbsp;<code>O(n)</code>&nbsp;time.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [100,4,200,1,3,2]
<strong>Output:</strong> 4
<strong>Explanation:</strong> The longest consecutive elements sequence is <code>[1, 2, 3, 4]</code>. Therefore its length is 4.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [0,3,7,2,5,8,4,6,0,1]
<strong>Output:</strong> 9
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>0 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>-10<sup>9</sup> &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    int longestConsecutive(vector<int>& nums) {
        if(nums.size()<2){return nums.size();}
        
        std:sort(nums.begin(),nums.end());
        std::set<int> uniqueElement(nums.begin(),nums.end());
        std::vector<int> array(uniqueElement.begin(),uniqueElement.end());

        for (int num : array) {
        std::cout << num << " ";
        }
        std::cout << std::endl;

        int longest = 1,tmp=1;

        for(int i=1;i<array.size();i++){

            if((array[i]-1) == array[i-1]){
                tmp++;
            }else{
                if(tmp>longest){longest = tmp;}
                tmp = 1;
            }
        }
        std::cout << std::endl;
        return max(longest,tmp);
    }
};
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