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.
1 <= intervals.length <= 10^4, intervals[i].length == 2
Sort by start time. Iterate and merge if current overlaps with previous (start <= prev end). Otherwise start new interval.
def merge(intervals):
intervals.sort(key=lambda x: x[0])
merged = [intervals[0]]
for start, end in intervals[1:]:
if start <= merged[-1][1]:
merged[-1][1] = max(merged[-1][1], end)
else:
merged.append([start, end])
return merged