Merge Intervals

 

    vector<Interval> merge(vector<Interval> &intervals) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        vector<Interval> res;
        if(intervals.empty())
            return res;
        sort(intervals.begin(),intervals.end(),cmp);
        res.push_back(intervals[0]);
        for(int i=1;i<intervals.size();i++)
        {
            Interval& t = res.back();
            if(intervals[i].start<=t.end)
                t.end = max(t.end,intervals[i].end);
            else
                res.push_back(intervals[i]);
        }
        return res;
    }