Can Place Flowers

问题：

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

解决：

①找到三个连续为0即可插入一个，所以只需要判断i - 1，i， i + 1这三个位置数值是否为空即可，然后，使用一个count计算插入的个数，若与n相等，则可以实现全部插入，否则不能。耗时15ms.

public class Solution {
public boolean canPlaceFlowers(int[] flowerbed, int n) {
if(n==0) return true;
if(flowerbed.length == 1 && flowerbed[0] == 0 && n <= 1){
return true;
}
int count = 0;
for (int i = 0;i < flowerbed.length ;i ++ ) {
if(flowerbed[i] == 0){
if((i == 0 && flowerbed[i + 1] == 0) ||
(i == flowerbed.length - 1 && flowerbed[i - 1] == 0) ||
(i !=0 && i != flowerbed.length - 1 && flowerbed[i - 1] == 0 && flowerbed[i + 1] == 0)){
flowerbed[i] =1;//若不加红色部分会造成数组下标越界。
count ++;
if (count == n) {
return true;
}
}
}
}
return false;
}
}