LeetCode: Can Place Flowers

Determine if a certain number of flowers can be planted in a flowerbed without violating the no-adjacent-flowers rule.

Solution

Hint: think about how you can skip over the greatest number of spots.

If there is a flower in the next spot, you can skip three spots ahead.

If there is a flower in the current spot, you can skip two spots ahead.

Notice that we never need to check the previous spot.

class Solution:
    def canPlaceFlowers(self, flowerbed: List[int], n: int) -> bool:
        i = 0
        while n > 0 and i < len(flowerbed):
            if i < len(flowerbed) - 1 and flowerbed[i + 1] == 1:
                i += 3
            elif flowerbed[i] == 1:
                i += 2
            else:
                flowerbed[i] = 1
                n -= 1
                i += 2

        return n == 0