02_MergeIntervals.py

# Question link - https://leetcode.com/problems/merge-intervals/?envType=study-plan-v2&envId=top-interview-150

class Solution:
    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
        n = len(intervals)
        intervals.sort()
        ans = []

        for i in range(n):
            if not ans or intervals[i][0] > ans[-1][1]:
                ans.append(intervals[i])
            # if the current interval
            # lies in the last interval:
            else:
                ans[-1][1] = max(ans[-1][1], intervals[i][1])

        return ans






#         # Approach 1 - Brute force

        # # Brute approch 
        # for i in range(n):
        #     start = intervals[i][0]
        #     end = internvals[i][1]

        #     # skip all the elements 
        #     if ans and end <= intervals[-1][1]:
        #         continue

        #     #check the rest of the intervals
        #     for j in range(i+1,n):
        #         if intervals[j][0] <= end:
        #             end = max(end , intervals[j][1])
        #         else:
        #             break
        #     ans.append([start , end])
        # return ans