56. Merge Intervals
Created: August 24, 2018 by [lek-tin]
Last updated: August 24, 2018
Given a collection of intervals, merge all overlapping intervals.
Example 1
Input: [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].
Example 2
Input: [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.
Solution
# Definition for an interval.
# class Interval:
# def __init__(self, s=0, e=0):
# self.start = s
# self.end = e
class Solution:
def merge(self, intervals):
"""
:type intervals: List[Interval]
:rtype: List[Interval]
"""
intervals.sort(key=lambda x : x.start)
merged = []
## [[1,3],[2,6],[8,10],[15,18]]
for interval in intervals:
# NO OVERLAP
if not merged or merged[-1].end < interval.start:
merged.append(interval)
# merge because last interval and the current interval OVERLAP
else:
merged[-1].end = max(merged[-1].end, interval.end)
return merged