Merge Intervals
Given an array of intervals where intervals[i] = [start_i, end_i], 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 since they share the endpoint 4.
Examples
Example 1
Input: intervals = [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Intervals [1,3] and [2,6] overlap, so they are merged into [1,6]. The remaining intervals do not overlap.
Example 2
Input: intervals = [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] share the endpoint 4, so they are merged into [1,5].
Example 3
Input: intervals = [[1,4],[0,4]]
Output: [[0,4]]
Explanation: The two intervals overlap completely, merging into [0,4].
Constraints
- -1 <= intervals.length <= 10^4
- -intervals[i].length == 2
- -0 <= start_i <= end_i <= 10^4
Optimal Complexity
Time
O(n log n)
Space
O(n)
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