56. Merge Intervals
Category: /leetcode| Leetcode Link | Interval Template |
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] overlaps, 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
Solution
Merge intervals: sort and merge
prefix sum
T: O(NlogN), S:O(N)
def merge(self, itnervals):
intervals.sort(key=lambda x: x[0])
res = [intervals[0]]
for interval in intervals[1:]:
if res[-1][1] < interval[0]:
res.append(interval)
else:
res[-1][1] = max(res[-1][1], interval[1])
return res
