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Merge Intervals

Problem Statement

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.

Examples

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

Code

Python3 Code

class Solution:
def merge(self, intervals: List[List[int]]) -> List[List[int]]:
if not intervals:
return []

sortedIntervals = sorted(intervals)
mergedIntervals = []

currentStart, currentEnd = sortedIntervals[0]

for start, end in sortedIntervals[1:]:
if start > currentEnd:
mergedIntervals.append((currentStart, currentEnd))
currentStart, currentEnd = start, end
else:
currentEnd = max(end, currentEnd)

mergedIntervals.append((currentStart, currentEnd))

return mergedIntervals