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.
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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. ++ +
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Constraints:
+ +1 <= intervals.length <= 104intervals[i].length == 20 <= starti <= endi <= 104