added Heap Sort

Sorting/HeapSort/HeapSort.cpp

@@ -0,0 +1,41 @@
+#include <bits/stdc++.h> 
+using namespace std; 
+void heapify(int arr[], int n, int i) 
+{ 
+    int largest = i; 
+    int l = 2*i + 1; 
+    int r = 2*i + 2;
+    if (l < n && arr[l] > arr[largest]) 
+        largest = l;
+    if (r < n && arr[r] > arr[largest]) 
+        largest = r;
+    if (largest != i) 
+    { 
+        swap(arr[i], arr[largest]);
+        heapify(arr, n, largest); 
+    } 
+}
+void heapSort(int arr[], int n) 
+{
+    for (int i = n / 2 - 1; i >= 0; i--) 
+        heapify(arr, n, i);
+    for (int i=n-1; i>=0; i--) 
+    {
+        swap(arr[0], arr[i]);
+        heapify(arr, i, 0); 
+    } 
+}
+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); 
+}