<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p>

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

<pre>
<strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]]
<strong>Output:</strong> [[1,6],[8,10],[15,18]]
<strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6].
</pre>

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

<pre>
<strong>Input:</strong> intervals = [[1,4],[4,5]]
<strong>Output:</strong> [[1,5]]
<strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping.
</pre>

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

<ul>
	<li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li>
	<li><code>intervals[i].length == 2</code></li>
	<li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li>
</ul>

class Solution {
public:
static bool cmp(pair<int,int> a, pair<int,int> b){
    if(a.first!=b.first)
        return a.first<b.first;
    else 
        return a.second<b.second;
}
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        vector<pair<int,int>>pairs;
        vector<vector<int>>ans;
        for(vector<int> v:intervals){
            pairs.push_back(make_pair(v[0],v[1]));
        }
        sort(pairs.begin(),pairs.end(),cmp);
        int start = pairs[0].first;
        int end = pairs[0].second;
        for(int i=1;i<pairs.size();i++){
            if(pairs[i].first<=end){
                end =max(end,pairs[i].second);
            }
            else{
                vector<int>temp;
                temp.push_back(start);
                temp.push_back(end);
                ans.push_back(temp);
                start = pairs[i].first;
                end = max(end,pairs[i].second);
                
            }
        }
        cout<<start<<" "<<end<<endl;
                vector<int>temp;
                temp.push_back(start);
                temp.push_back(end);
                ans.push_back(temp);
        return ans;

    }
};
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