leetcode-56-合并区间

题目描述：

 

方法一：O(nlogn)

class Solution:
    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
        intervals.sort(key=lambda intervals:intervals[0])
        merge = []
        for i in intervals:
            if not merge or merge[-1][1]<i[0]:
                merge.append(i)
            else:
                merge[-1][1] = max(i[1],merge[-1][1])    
        return merge