Day048 - 56. Merge Intervals

56. Merge Intervals

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input.

Example 1:

Input: intervals = [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlap, merge them into [1,6].

Example 2:

Input: intervals = [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.

Constraints:

• 1 <= intervals.length <= 104
• intervals[i].length == 2
• 0 <= starti <= endi <= 104

내 풀이

from collections import deque

class Solution:
    def merge(self, intervals: List[List[int]]) -> List[List[int]]:

        intervals = sorted(intervals, key=lambda x: x[0])
        
        intervals = deque(intervals)
        first_interval = intervals.popleft()
        l, r = first_interval[0], first_interval[1]

        answer = []
        while intervals:
            next_interval = intervals.popleft()
            next_l, next_r = next_interval[0], next_interval[1]

            if next_l >= l and next_r <= r:
                continue

            if r >= next_l:
                r = next_r
                continue

            answer.append([l, r])
            l, r = next_l, next_r

        answer.append([l, r])

        return answer

# Time Complexity : \(O(N)\)