動機

比起對起點做特別處理，全部列出來再把不合法的濾掉會比較簡單

Problem

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots.

Given an integer array flowerbed containing 0's and 1's, where 0 means empty and 1 means not empty, and an integer n, return if n new flowers can be planted in the flowerbed without violating the no-adjacent-flowers rule.

 

Example 1:

Input: flowerbed = [1,0,0,0,1], n = 1Output: true

Example 2:

Input: flowerbed = [1,0,0,0,1], n = 2Output: false

 

Constraints:

  • 1 <= flowerbed.length <= 2 * 104
  • flowerbed[i] is 0 or 1.
  • There are no two adjacent flowers in flowerbed.
  • 0 <= n <= flowerbed.length

Sol

class Solution:
    def canPlaceFlowers(self, flowerbed: List[int], n: int, i = 0) -> bool:
        if n == 0:
            return True
        elif i >= len(flowerbed):
            return False
        elif any(flowerbed[x] == 1 for x in [x for x in [i-1,i,i+1] if 0 <= x < len(flowerbed)]):
            return self.canPlaceFlowers(flowerbed,n,i+1)
        else:
            flowerbed[i] = 1
            return self.canPlaceFlowers(flowerbed,n-1,i+1)