Merge Intervals

main.py

class Solution:
    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
        if len(intervals) == 0:
            return []
        merged_intervals = []
        intervals.sort()

        l1, r1 = intervals[0]
        for i in range(1, len(intervals)):
            l2, r2 = intervals[i]
            if l2 <= r1:
                r1 = max(r1, r2)
            else:
                merged_intervals.append([l1, r1])
                l1, r1 = l2, r2

        merged_intervals.append([l1, r1])

        return merged_intervals