Added Heap Sort

Author: mujtaba1747

Sorting Algorithm/Heap Sort/C++/heap_sort.cpp

@@ -0,0 +1,66 @@
+// 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"; 
+} 
+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); 
+}