-> std::vector<std::pair<int, int>>

{

// if array is empty

if (intervals.empty())

{

return {};

}

// sort intervals by start time

std::ranges::sort(intervals, [](const std::pair<int, int>& a, const std::pair<int, int>& b) {

return a.first < b.first;

});

std::vector<std::pair<int, int>> result;

result.push_back(intervals[0]);

for (const auto& interval : intervals)

{

// if current interval overlaps with the previous

if (interval.first <= result.back().second)

{

result.back().second = std::max(result.back().second, interval.second);

}

else

{

result.push_back(interval);

}

}

return result;