LeetCode 605. Can Place Flowers

Intuition

To check condition in an easier manner, add 0 at the beginning and the end

1. Iterate through flowerbed and if i-1 and i and i+1 are all 0, change the current element to 1
2. subtract 1 from n
3. End the loop if n less than equal to 0
4. return n less than equal to 0 at the end to check whether all flowers were planted

Optimal Solution

class Solution:
	def canPlaceFlowers(self, flowerbed: List[int], n:int) -> bool:
		arr = [0] + flowerbed + [0]
		
		for i in range(1,len(arr)-1):
			if arr[i-1] == 0 and arr[i] and arr[i+1] == 0:
				arr[i] = 1
				n -= 1
				
			if n <= 0:
				return True
				
		return n <= 0

Time Complexity

Time Complexity O(N)

Space Complexity O(N)