create heap sort in c++

Author: avi181197

heap sort.cpp

@@ -0,0 +1,65 @@
+// C++ program for implementation of Heap Sort 
+#include <iostream> 
+using namespace std; 
+  
+// To heapify a subtree rooted with node i which is 
+// an index in arr[]. n is size of heap 
+void heapify(int arr[], int n, int i) 
+{ 
+    int largest = i; // Initialize largest as root 
+    int l = 2 * i + 1; // left = 2*i + 1 
+    int r = 2 * i + 2; // right = 2*i + 2 
+  
+    // If left child is larger than root 
+    if (l < n && arr[l] > arr[largest]) 
+        largest = l; 
+  
+    // If right child is larger than largest so far 
+    if (r < n && arr[r] > arr[largest]) 
+        largest = r; 
+  
+    // If largest is not root 
+    if (largest != i) { 
+        swap(arr[i], arr[largest]); 
+  
+        // Recursively heapify the affected sub-tree 
+        heapify(arr, n, largest); 
+    } 
+} 
+  
+// main function to do heap sort 
+void heapSort(int arr[], int n) 
+{ 
+    // Build heap (rearrange array) 
+    for (int i = n / 2 - 1; i >= 0; i--) 
+        heapify(arr, n, i); 
+  
+    // One by one extract an element from heap 
+    for (int i = n - 1; i >= 0; i--) { 
+        // Move current root to end 
+        swap(arr[0], arr[i]); 
+  
+        // call max heapify on the reduced heap 
+        heapify(arr, i, 0); 
+    } 
+} 
+  
+/* A utility function to print array of size n */
+void printArray(int arr[], int n) 
+{ 
+    for (int i = 0; i < n; ++i) 
+        cout << arr[i] << " "; 
+    cout << "\n"; 
+} 
+  
+// Driver program 
+int main() 
+{ 
+    int arr[] = { 12, 11, 13, 5, 6, 7 }; 
+    int n = sizeof(arr) / sizeof(arr[0]); 
+  
+    heapSort(arr, n); 
+  
+    cout << "Sorted array is \n"; 
+    printArray(arr, n); 
+}