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 nnew 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.

public class Solution {
    public boolean canPlaceFlowers(int[] flowerbed, int n) {
        int len = flowerbed.length;
        if (len == 1) return !(flowerbed[0] == 1 && n >= 1);
        
        for (int i = 0; i < len; i++) {
            if (flowerbed[i] == 0) {
                int zeros = 0, j = i;
                while (j < len && flowerbed[j] == 0) {
                    zeros++;
                    j++;
                }
                
                if (j < len && i > 0) n -= (zeros - 1) / 2;
                else if (i == 0 && j == len) n -= (zeros + 1) / 2;
                else n -= zeros / 2;
                
                i = j;
            }
        }
        return n <= 0;
    }
}