Merge Intervals

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

Function signature

func MergeIntervals(intervals [][]int) [][]int

Example

intervals = [[1,3],[2,6],[8,10],[15,18]]
output = [[1,6],[8,10],[15,18]]

Constraints

• 0 <= len(intervals) <= 100_000
• intervals[i] has length 2
• -1_000_000_000 <= start <= end <= 1_000_000_000

Notes

• Sort by start, then sweep and merge in O(n log n).