Leetcode#56 Merge Intervals

 1 vector<Interval> merge(vector<Interval> &intervals) {
 2   vector<Interval> result;
 3 
 4   sort(intervals.begin(), intervals.end(), [](Interval a, Interval b) {
 5       return a.start < b.start || (a.start == b.start && a.end < b.end);
 6   });
 7 
 8   for (auto itv : intervals) {
 9     if (result.empty() || result.back().end < itv.start)
10       result.push_back(itv);
11     else
12       result.back().end = max(result.back().end, itv.end);
13   }
14 
15   return result;
16 }