Added Heapsort for C

Author: JMJ2312

src/c/Heapsort.c

@@ -0,0 +1,66 @@
+#include <stdio.h>
+
+void heapify(int arr[], int n, int i)
+{
+    int largest = i;
+    int left = 2 * i + 1;
+    int right = 2 * i + 2;
+
+    if (left < n && arr[left] > arr[largest])
+        largest = left;
+
+    // If the right child is larger than the largest so far
+    if (right < n && arr[right] > arr[largest])
+        largest = right;
+
+    // If the largest element is not the root
+    if (largest != i)
+    {
+        // Swap the largest element with the root
+        int temp = arr[i];
+        arr[i] = arr[largest];
+        arr[largest] = temp;
+
+        // Recursively heapify the affected sub-tree
+        heapify(arr, n, largest);
+    }
+}
+
+void heapsort(int arr[], int n)
+{
+    // Build a max heap
+    int i;
+    for (i = n / 2 - 1; i >= 0; i--)
+        heapify(arr, n, i);
+
+    // One by one extract elements from the heap
+    for (i = n - 1; i > 0; i--)
+    {
+        // Move the current root to the end
+        int temp = arr[0];
+        arr[0] = arr[i];
+        arr[i] = temp;
+
+        // Call max heapify on the reduced heap
+        heapify(arr, i, 0);
+    }
+}
+
+int main()
+{
+    int arr[] = {12, 21, 13, 5, 1, 7};
+    int i;
+    int n = sizeof(arr) / sizeof(arr[0]);
+
+    printf("Original array: ");
+    for (i = 0; i < n; i++)
+        printf("%d ", arr[i]);
+
+    heapsort(arr, n);
+
+    printf("\nSorted array: ");
+    for (i = 0; i < n; i++)
+        printf("%d ", arr[i]);
+
+    return 0;
+}