605. Can Place Flowers
https://leetcode.com/problems/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:
- 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.
--
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| class Solution { | |
| public boolean canPlaceFlowers(int[] flowerbed, int n) { | |
| if (flowerbed == null || flowerbed.length < n) { | |
| return false; | |
| } | |
| for (int i = 0; i < flowerbed.length; i++) { | |
| // expressions to avoid index out of bounds | |
| if (flowerbed[i] == 0 && (i == 0 || flowerbed[i - 1] == 0) && (i == flowerbed.length - 1 || flowerbed[i + 1] == 0)) { | |
| flowerbed[i] = 1; | |
| n--; | |
| if (n == 0) { | |
| return true; | |
| } | |
| } | |
| } | |
| return n <= 0; // corner case - validate input | |
| } | |
| } |
