[leetcode] Merge Intervals - Python

原题地址：https://oj.leetcode.com/problems/merge-intervals/

题意：

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].

解题思路：先将区间按照每个start的值来排序，排好序以后判断一个区间的start值是否处在前一个区间中，如果在前一个区间中，那么合并；如果不在，就将新区间添加。

代码：

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

class Solution:
    # @param intervals, a list of Interval
    # @return a list of Interval
    def merge(self, intervals):
        intervals.sort(key = lambda x:x.start)
        length=len(intervals)
        res=[]
        for i in range(length):
            if res==[]:
                res.append(intervals[i])
            else:
                size=len(res)
                if res[size-1].start<=intervals[i].start<=res[size-1].end:
                    res[size-1].end=max(intervals[i].end, res[size-1].end)
                else:
                    res.append(intervals[i])
        return res