merge-intervals.py

class Solution:
    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
        intervals.sort()
        idx = 0
        for i in range(1, len(intervals)):
            if intervals[i][0] <= intervals[idx][1]:
                intervals[idx][1] = max(intervals[idx][1], intervals[i][1])
            else:
                idx += 1
                intervals[idx] = intervals[i]
        return intervals[:idx+1]