[LeetCode] 605. Can Place Flowers_Easy

Suppose 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 - they would compete for water and both would die.

Given a flowerbed (represented as an array containing 0 and 1, where 0 means empty and 1 means not empty), and a number n, return if n new flowers can be planted in it without violating the no-adjacent-flowers rule.

Example 1:

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

Example 2:

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

Note:

1. The input array won't violate no-adjacent-flowers rule.
2. The input array size is in the range of [1, 20000].
3. n is a non-negative integer which won't exceed the input array size.

思路就是监测, 如果左中右都为0, 那么加1, 并把当前的位置置1, 最后判断ans>=n

Code

class Solution(object):
    def canPlaceFlowers(self, flowerbed, n):
        """
        :type flowerbed: List[int]
        :type n: int
        :rtype: bool
        """
        fb, ans = [0] + flowerbed + [0], 0
        for i in range(1, len(fb) -1):
            if fb[i-1] == fb[i] == fb[i+1] == 0:
                fb[i] = 1
                ans += 1
        return ans >= n