题目：

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：

本题，只要就算可以插花的个数，每连续三个0可以插一朵花，但是要注意首尾为0的特殊情况

代码：

class Solution {
public:
    bool canPlaceFlowers(vector<int>& flowerbed, int n) {
        int i = 0;
        while(i<flowerbed.size())
        {
            if(flowerbed[i]==0&&(i==0||flowerbed[i-1]==0)&&(i==flowerbed.size()-1||flowerbed[i+1]==0))
            {
                n--;
                flowerbed[i] = 1;
            }
            i++;
        }
    return n<1?true:false;
    }
};