Merge Intervals

Problem

Given an array of intervals, merge all overlapping intervals and return the non-overlapping set.

Example

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

Constraints

• 1 ≤ intervals.length ≤ 10^4

Approach

Sort by start, then sweep merging when current.start ≤ prev.end.