Merge Intervals — Python

# Time:  O(nlogn)
# Space: O(1)

class Solution(object):
    def merge(self, intervals):
        """
        :type intervals: List[List[int]]
        :rtype: List[List[int]]
        """
        intervals.sort()
        result = []
        for interval in intervals:
            if not result or interval[0] > result[-1][1]:
                result.append(interval)
            else:
                result[-1][1] = max(result[-1][1], interval[1])
        return result