Merge Intervals

'''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.'''

class Solution(object):
    def merge(self, intervals):
        """
        :type intervals: List[List[int]]
        :rtype: List[List[int]]
        """
        # print(sorted(intervals, key=lambda j: j[0]))
        final = []
        for i in sorted(intervals, key=lambda j: j[0]):
            if final and (i[0]<=final[-1][1]):
                final[-1][1] = max(final[-1][1], i[1])
            else:
                final.append(i)
            
        return(final)