[leetcode]Merge Intervals @ Python

原題地址：https://oj.leetcode.com/problems/merge-intervals/

題意：

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].

解題思路：先將區間按照每個start的值來排序，排好序以后判斷一個區間的start值是否處在前一個區間中，如果在前一個區間中，那么合並；如果不在，就將新區間添加。

代碼：

# 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