From 358fa077350bc1bd9a0dfad11748c2b1fe6eeb2c Mon Sep 17 00:00:00 2001
From: thebrahminator <vishwa.nath@outlook.com>
Date: Tue, 2 Oct 2018 21:41:04 +0530
Subject: [PATCH] This add Heap Sort

This adds Heap Sort to the repository.

Closes https://github.com/AllAlgorithms/cpp/issues/6
---
 README.md             |  2 +-
 sorting/heap_sort.cpp | 60 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 sorting/heap_sort.cpp

diff --git a/README.md b/README.md
index 6886d0f2..13a9454d 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@
 - [Sorting](sorting)
 - [Strings](strings)
 - [Traversals](traversals)
-
+- [Heap Sort](sorting/heap_sort.cpp)
 ## License
 
 This work is licensed under a [MIT License](https://github.com/abranhe/algorithms/blob/master/LICENSE)
diff --git a/sorting/heap_sort.cpp b/sorting/heap_sort.cpp
new file mode 100644
index 00000000..4862b94f
--- /dev/null
+++ b/sorting/heap_sort.cpp
@@ -0,0 +1,60 @@
+#include <iostream> 
+  
+using namespace std; 
+
+void heapify(int input[], int n, int i) 
+{ 
+
+    int largest = i; // Assign the largest as root
+    int left = 2*i + 1;  // Calculate the index of left element
+    int right = 2*i + 2; // Calculate the index of right element
+  
+    //Checking if the left is larger than current large value
+    if (left < n && input[left] > input[largest]) 
+        largest = left; 
+    
+    //Checking if the right is larger than current large value
+    if (right < n && input[right] > input[largest]) 
+        largest = right; 
+        
+    if (largest != i) 
+    { 
+        swap(input[i], input[largest]); 
+  
+        heapify(input, n, largest); 
+    } 
+} 
+  
+void heapSort(int input[], int n) 
+{   // Function to perform heap sort. 
+
+    // Building the heap, effectively rearranging the array.
+    for (int i = n / 2 - 1; i >= 0; i--) 
+        heapify(input, n, i); 
+
+    for (int i=n-1; i>=0; i--) 
+    { 
+        swap(input[0], input[i]); 
+        heapify(input, i, 0); 
+    } 
+}
+
+int main() 
+{   
+    int n;
+    cout<<"Enter the number of elements"<<endl;
+    cin>>n;
+    int array[n];
+    cout<<"Enter the elements of array"<<endl;
+    
+    for(int i=0; i<n; i++){
+        cin>>array[i];
+    }
+    heapSort(array, n); 
+    cout << "Sorted array is \n"; 
+    for(int i=0; i<n; i++){
+        cout<<array[i]<<" ";
+    }
+    cout<<endl;
+    return 1;
+}