Can Place Flowers

class Solution {
public:
    bool canPlant(vector<int>& garden, int n) {
        int planted = 0;
        for (int i = 0; i < garden.size(); i++) {
            if (garden[i] == 0) {
                bool leftSafe = (i == 0) || (garden[i - 1] == 0);
                bool rightSafe = (i == garden.size() - 1) || (garden[i + 1] == 0);
                
                if (leftSafe && rightSafe) {
                    garden[i] = 1;
                    planted++;
                    if (planted >= n) {
                        return true;
                    }
                }
            }
        }
        return planted >= n;
    }
};

The provided C++ code defines a solution to determine whether it's possible to plant a specified number of flowers (n) in a garden while adhering to specific constraints. The garden layout is represented as a vector (garden), where 0 indicates an empty plot and 1 indicates a plot with a flower already planted.

• The canPlant function iterates over each plot in the garden.
• For each plot, it checks if the plot itself is empty (0).
• If a plot is found to be empty, the function then checks two conditions:
  • leftSafe: checks if the current plot is either the first plot or if the plot to the left is empty.
  • rightSafe: checks if the current plot is either the last plot in the garden or if the plot to the right is empty.
• If both leftSafe and rightSafe are true, indicating no adjacent flowers, the function plants a flower at the current plot by setting its value to 1 and increments the planted counter.
• This process continues until the number of planted flowers reaches or exceeds n. If this happens before all plots are checked, the function immediately returns true.
• If the loop completes and the number of planted flowers is still less than n, it returns false.

This approach ensures optimization by potentially terminating early if the required number of flowers are successfully planted before reaching the end of the garden array.

public class Solution {
    public boolean validatePlanting(int[] garden, int n) {
        int planted = 0;
        for (int index = 0; index < garden.length; index++) {
            if (garden[index] == 0) {
                boolean leftSafe = (index == 0) || (garden[index - 1] == 0);
                boolean rightSafe = (index == garden.length - 1) || (garden[index + 1] == 0);

                if (leftSafe && rightSafe) {
                    garden[index] = 1;
                    planted++;
                    if (planted >= n) {
                        return true;
                    }
                }
            }
        }
        return planted >= n;
    }
}

The "Can Place Flowers" problem involves determining if it's possible to plant n flowers in a specific arrangement such that no two flowers are adjacent to each other. The solution is implemented in Java with a method called validatePlanting that takes two parameters, an array garden where 0 represents an empty space and 1 represents a planted flower, and an integer n which is the number of flowers you aim to plant.

Follow this process in the given Java code:

1. Initialize planted as 0 to track the number of planted flowers.
2. Loop through each position in the garden array:
   • Check if the current position (index) is empty (garden[index] == 0).
   • Ensure the left and right positions relative to the current position are safe to plant a flower. The left position is safe if it is the first position or the element before it is 0. The right position is safe if it is the last position or the element after it is 0.
   • If both conditions are satisfied, plant a flower at the current position by setting it to 1, and increment the planted count.
   • If the number of planted flowers reaches or exceeds n, immediately return true.
3. After the loop, check if the number of planted flowers meets the required count (n). Return true if it meets or exceeds the requirement, otherwise return false.

This implementation efficiently checks each possible spot in the garden array only once, and terminates early if the target number of flowers has been planted, enhancing performance for larger inputs.

class Solution:
    def canPlant(self, garden: List[int], k: int) -> bool:
        flowers_planted = 0
        for idx in range(len(garden)):
            if garden[idx] == 0:
                left_open = (idx == 0) or (garden[idx - 1] == 0)
                right_open = (idx == len(garden) - 1) or (garden[idx + 1] == 0)
                
                if left_open and right_open:
                    garden[idx] = 1
                    flowers_planted += 1
                    if flowers_planted >= k:
                        return True
                    
        return flowers_planted >= k

The given code defines a method canPlant within the Solution class. This method determines if it's possible to plant k flowers in a given garden, represented as a list where 0 indicates an empty plot and 1 indicates a plot that's occupied by another flower.

Here's how the method executes:

• Initialize flowers_planted to 0 to keep track of the number of flowers planted.
• Loop through each plot in the garden:
  • Verify if the current plot (idx) is 0 (empty).
  • Ensure the plot to the left (left_open) is either the first plot or is empty.
  • Ensure the plot to the right (right_open) is either the last plot or is empty.
  • If both left and right plots meet the conditions, set the current plot to 1 (plant a flower) and increase flowers_planted by 1.
  • If at any point, the number of flowers_planted equals or surpasses k, return True.
• After exiting the loop, if flowers_planted is still less than k, return False.

This approach ensures that the function respects garden planting rules: no two flowers can be adjacent. The solution appropriately checks all conditions to guarantee each flower has adequate space, leveraging boolean checks for edge cases at the garden's boundaries.