Cinemas in 2021

Given a list of seats, return the maximum number of new people which can be seated, as long as there is at least a gap of 2 seats between people.

• Empty seats are given as 0.
• Occupied seats are given as 1.
• Don't move any seats which are already occupied, even if they are less than 2 seats apart. Consider only the gaps between new seats and existing seats.

Examples

maximum_seating([0, 0, 0, 1, 0, 0, 1, 0, 0, 0]) ➞ 2
# [1, 0, 0, 1, 0, 0, 1, 0, 0, 1]

maximum_seating([0, 0, 0, 0]) ➞ 2
# [1, 0, 0, 1]

maximum_seating([1, 0, 0, 0, 0, 1]) ➞ 0
# There is no way to have a gap of at least 2 chairs when adding someone else.

Notes

• Notice how there may be several possibilities for assigning seats to people, but these cases won't affect the results.
• All seats will be valid.