<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:

    static bool comparator(vector<int> &a,vector<int> &b){
        if(a[0]==b[0]){
            return a[1]>b[1];
        }
        return a[0]<b[0];
    }

    int removeCoveredIntervals(vector<vector<int>>& intervals) {
        sort(intervals.begin(),intervals.end(), comparator);
        int n = intervals.size();
        int mx = INT_MIN;
        int out = n;
        for(int i = 0; i<n; i++){
            if(intervals[i][1]<=mx) out--;
            mx = max(mx,intervals[i][1]);
            // cout<<intervals[i][0]<<' '<<intervals[i][1]<<endl;
        }
        return out;
    }
};
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