<p>Given an array <code>intervals</code> where <code>intervals[i] = [l<sub>i</sub>, r<sub>i</sub>]</code> represent the interval <code>[l<sub>i</sub>, r<sub>i</sub>)</code>, remove all intervals that are covered by another interval in the list.</p>

<p>The interval <code>[a, b)</code> is covered by the interval <code>[c, d)</code> if and only if <code>c &lt;= a</code> and <code>b &lt;= d</code>.</p>

<p>Return <em>the number of remaining intervals</em>.</p>

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

<pre>
<strong>Input:</strong> intervals = [[1,4],[3,6],[2,8]]
<strong>Output:</strong> 2
<strong>Explanation:</strong> Interval [3,6] is covered by [2,8], therefore it is removed.
</pre>

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

<pre>
<strong>Input:</strong> intervals = [[1,4],[2,3]]
<strong>Output:</strong> 1
</pre>

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

<ul>
	<li><code>1 &lt;= intervals.length &lt;= 1000</code></li>
	<li><code>intervals[i].length == 2</code></li>
	<li><code>0 &lt;= l<sub>i</sub> &lt; r<sub>i</sub> &lt;= 10<sup>5</sup></code></li>
	<li>All the given intervals are <strong>unique</strong>.</li>
</ul>

class Solution {
public:
    struct comp{
        bool operator()(pair<int,int> p1,pair<int,int> p2){
            if(p1.first==p2.first)
                return p1.second<p2.second;
            return p1.first>p2.first;
        }
    };
    
    int removeCoveredIntervals(vector<vector<int>>& intervals) {
        priority_queue<pair<int,int>,vector<pair<int,int>>,comp> pq;
        
        for(int i=0;i<intervals.size();i++)pq.push({intervals[i][0],intervals[i][1]});
        
        int x=0;
        int start=pq.top().first;
        int end=pq.top().second;
        pq.pop();
        
        while(pq.size()!=0){
            pair<int,int> p=pq.top();pq.pop();
            if(p.first>=start && p.second<=end)x++;
            start=min(start,p.first);
            end=max(end,p.second);
        }
        cout<<x;
        return intervals.size()-x;
    }
};
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