Merge Intervals - Leetcode 56 - Python

 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.

Example 1:

Input: intervals = [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlap, merge them into [1,6].

Example 2:

Input: intervals = [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.

 

Constraints:

• 1 <= intervals.length <= 104
• intervals[i].length == 2
• 0 <= starti <= endi <= 104

class Solution:

    def merge(self, v: List[List[int]]) -> List[List[int]]:

        # [[1,3],[2,6],[8,10],[15,18]]

        v.sort(key = lambda i : i[0])

        ans = [v[0]] #[[1,3]]

        

        for f,t in v[1:] :

            l2 = ans[-1][1] # l2 = 3 

            

            if f <= l2 : #[2,6]

                ans[-1][1] = max(l2, t)

            else:

                ans.append([f,t])

        return ans

        

        

Explaination :