feat: add LeetCode problem 605

leetcode/src/605.c

@@ -0,0 +1,69 @@
+/**
+ * Determines if n new flowers can be planted in the flowerbed without violating
+ * the no-adjacent-flowers rule. Approach: Iterate through the flowerbed array,
+ * checking for spots where a flower can be planted (i.e., where the current
+ * spot and its adjacent spots are empty). Update the flowerbed array to reflect
+ * the planting and increment a counter. Stop if the required number of flowers
+ * (n) has been planted.
+ *
+ * Time Complexity: O(flowerbedSize), as we iterate through the flowerbed array
+ * once. Space Complexity: O(1), as we use a fixed amount of space regardless of
+ * the input size.
+ *
+ * @param flowerbed Pointer to the array representing the flowerbed, where 0
+ * indicates an empty spot and 1 indicates a flower.
+ * @param flowerbedSize The size of the flowerbed array.
+ * @param n The number of flowers we wish to plant.
+ * @return True if it is possible to plant n flowers without violating the rule
+ * that no two flowers can be adjacent, otherwise false.
+ */
+bool canPlaceFlowers(int* flowerbed, int flowerbedSize, int n)
+{
+    // Handle edge case: single empty spot in flowerbed
+    if (flowerbedSize == 1 && flowerbed[0] == 0)
+        return true;
+
+    int count = 0;  // Counter for the number of flowers planted
+    for (int i = 0; i < flowerbedSize; i++)
+    {
+        // Check if current spot is empty
+        if (flowerbed[i] != 1)
+        {
+            if (i == 0)
+            {
+                // Special case for the first element: check if the next element
+                // is empty
+                if (flowerbed[i + 1] == 0)
+                {
+                    flowerbed[i] = 1;  // Plant flower
+                    count++;
+                }
+            }
+            else if (i == flowerbedSize - 1)
+            {
+                // Special case for the last element: check if the previous
+                // element is empty
+                if (flowerbed[i - 1] == 0)
+                {
+                    flowerbed[i] = 1;  // Plant flower
+                    count++;
+                }
+            }
+            else
+            {
+                // For middle elements, check both previous and next elements
+                // are empty
+                if (flowerbed[i - 1] == 0 && flowerbed[i + 1] == 0)
+                {
+                    flowerbed[i] = 1;  // Plant flower
+                    count++;
+                }
+            }
+        }
+        // Check if the required number of flowers has been planted
+        if (count >= n)
+            return true;
+    }
+    // Return false if unable to plant the required number of flowers
+    return false;
+}