605. Can Place Flowers
1. Description
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.
2. Example
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
3. Constraints
- 1 <= flowerbed.length <= $2 * 10^4$
- flowerbed[i] is 0 or 1.
- There are no two adjacent flowers in flowerbed.
- 0 <= n <= flowerbed.length
4. Solutions
My Accepted Solution
n = m_flowerbed.size()
Time complexity: O(n)
Space complexity: O(1)
// greedy
class Solution
{
public:
// bool canPlaceFlowers(vector<int>& flowerbed, int n)
bool canPlaceFlowers(vector<int> &m_flowerbed, int count)
{
if(count == 0) return true;
if(m_flowerbed.size() == 1) return (m_flowerbed.front() == 0 && count == 1);
for(int i = 0; i < m_flowerbed.size(); i++)
{
if(m_flowerbed[i] == 0 &&
((i == 0 && m_flowerbed[i + 1] == 0)
|| (i == m_flowerbed.size() - 1 && m_flowerbed[i - 1] == 0)
|| (0 < i && i < m_flowerbed.size() - 1 && m_flowerbed[i - 1] == 0 && m_flowerbed[i + 1] == 0))
)
{
m_flowerbed[i] = 1;
count--;
}
if(count == 0) return true;
}
return false;
}
};