Merge Intervals

1def merge(intervals: List[List[int]]) -> List[List[int]]:
2    intervals.sort(key=lambda x: x[0])
3    res = [intervals[0]]
4    
5    for s, e in intervals[1:]:
6        last = res[-1]
7        if s <= last[1]:
8            last[1] = max(last[1], e)
9        else:
10            res.append([s, e])
11    
12    return res