## Description

https://leetcode.com/problems/merge-intervals/

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.

**NOTE:** input types have been changed on April 15, 2019. Please reset to default code definition to get new method signature.

## Explanation

base on start and end to merge interval

## Python Solution

```
class Solution:
def merge(self, intervals: List[List[int]]) -> List[List[int]]:
result = []
intervals = sorted(intervals, key=lambda interval:interval[0])
for interval in intervals:
if len(result) == 0 or result[-1][1] < interval[0]:
result.append(interval)
else:
result[-1][1] = max(result[-1][1], interval[1])
return result
```

- Time complexity: ~ N
- Space complexity: ~1

## One Thought to “LeetCode 56. Merge Intervals”