605. Can Place Flowers

605. Can Place Flowers

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.

My Solutions：

检查每一个index前面的和后面的位置，如果都是0，则可以种花，count++，位置记录成1。注意第一个和最后一个，第一个的前面相当于是0，最后一个的后面相当于是0。

class Solution {
    public boolean canPlaceFlowers(int[] flowerbed, int n) {
        
        int count = 0;
        
        for(int i = 0; i < flowerbed.length && count < n; i++){
            if(flowerbed[i] == 0){
                int next = (i == flowerbed.length - 1) ? 0 : flowerbed[i + 1];
                int prev = (i == 0) ? 0 : flowerbed[i - 1];
                if(next == 0 && prev == 0){ //都是空白可以种花
                    flowerbed[i] = 1;
                    count++;
                } 
                if (count >= n) return true;
            }
        }
        return false;
    }
}