Merge Intervals

Given a collection of intervals, merge all overlapping intervals.

For example,

Given [1,3],[2,6],[8,10],[15,18],

return [1,6],[8,10],[15,18].

注意sorted用法

# Definition for an interval.
# class Interval(object):
#     def __init__(self, s=0, e=0):
#         self.start = s
#         self.end = e

class Solution(object):
    def merge(self, intervals):
        """
        :type intervals: List[Interval]
        :rtype: List[Interval]
        """
        res = []
        for val in sorted(intervals, key=lambda i: i.start):
            if res and res[-1].end >= val.start:
                res[-1].end = max(res[-1].end, val.end)
            else:
                res += val,
        return res