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:
The input array won't violate no-adjacent-flowers rule.
The input array size is in the range of [1, 20000].
n is a non-negative integer which won't exceed the input array size.
Solution:
class Solution {
public boolean canPlaceFlowers(int[] flowerbed, int n) {
int num = 0;
for (int i = 0; i < flowerbed.length; i ++) {
if ( (i == 0 || flowerbed[i - 1] == 0) && flowerbed[i] == 0 && (i == flowerbed.length - 1 || flowerbed[i + 1] == 0)) {
flowerbed[i] = 1;
num ++;
if (num >= n) return true;
}
}
return num >= n;
}
}