605. Can Place Flowers

From software interview series, this leetcode excercise will help you practice for your tech interview. https://leetcode.com/problems/can-place-flowers/

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.

Given an integer array flowerbed containing 0's and 1's, where 0 means empty and 1 means not empty, and an integer n, return if n new flowers can be planted in the flowerbed 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

Constraints:

• 1 <= flowerbed.length <= 2 * 104
• flowerbed[i] is 0 or 1.
• There are no two adjacent flowers in flowerbed.
• 0 <= n <= flowerbed.length

Result:

Runtime: 0 ms

Memory Usage: 40.5 MB

You are free to continue working on this question, but please note that only your first accepted submission will be counted.

Solution:

class Solution {
    public boolean canPlaceFlowers(int[] flowerbed, int n) {
        if(flowerbed == null || flowerbed.length == 0 ) return false;
        if(n==0 ) return true;
        
        int pos=0;
        while(pos < flowerbed.length){
            if(flowerbed[pos] == 0  ){
                if( (pos == flowerbed.length-1 ) || (0 == flowerbed[pos+1]) ){   //found an spot
                     n--;  
                }else{      //adjacent plant afterwards so we move there
                    pos++;
                }
            }
            
            if( n ==0 ){
                return true;
            }
            pos+=2;
        }
        return false;
    }
}