Here is the source code of the program to implement heap C++ programming language.
#include <iostream>
#include <cstdlib>
#include <vector>
#include <iterator>
using namespace std;
// Class Declaration
class Heap
{
private:
vector <int> heap;
int left(int parent);
int right(int parent);
int parent(int child);
void heapifyup(int index);
void heapifydown(int index);
public:
Heap()
{}
void Insert(int element);
void DeleteMin();
int ExtractMin();
void DisplayHeap();
int Size();
};
// Return Heap Size
int Heap::Size()
{
return heap.size();
}
// Insert Element into a Heap
void Heap::Insert(int element)
{
heap.push_back(element);
heapifyup(heap.size() -1);
}
// Delete Minimum Element
void Heap::DeleteMin()
{
if (heap.size() == 0)
{
cout<<"Heap is Empty"<<endl;
return;
}
heap[0] = heap.at(heap.size() - 1);
heap.pop_back();
heapifydown(0);
cout<<"Element Deleted"<<endl;
}
// Extract Minimum Element
int Heap::ExtractMin()
{
if (heap.size() == 0)
{
return -1;
}
else
return heap.front();
}
// Display Heap
void Heap::DisplayHeap()
{
vector <int>::iterator pos = heap.begin();
cout<<"Heap --> ";
while (pos != heap.end())
{
cout<<*pos<<" ";
pos++;
}
cout<<endl;
}
// Return Left Child
int Heap::left(int parent)
{
int l = 2 * parent + 1;
if(l < heap.size())
return l;
else
return -1;
}
// Return Right Child
int Heap::right(int parent)
{
int r = 2 * parent + 2;
if(r < heap.size())
return r;
else
return -1;
}
// Return Parent
int Heap::parent(int child)
{
int p = (child - 1)/2;
if(child == 0)
return -1;
else
return p;
}
// Heapify- Maintain Heap Structure bottom up
void Heap::heapifyup(int in)
{
if (in >= 0 && parent(in) >= 0 && heap[parent(in)] > heap[in])
{
int temp = heap[in];
heap[in] = heap[parent(in)];
heap[parent(in)] = temp;
heapifyup(parent(in));
}
}
// Heapify- Maintain Heap Structure top down
void Heap::heapifydown(int in)
{
int child = left(in);
int child1 = right(in);
if (child >= 0 && child1 >= 0 && heap[child] > heap[child1])
{
child = child1;
}
if (child > 0)
{
int temp = heap[in];
heap[in] = heap[child];
heap[child] = temp;
heapifydown(child);
}
}
// Main Contains Menu
int main()
{
Heap h;
while (1)
{
cout<<"------------------"<<endl;
cout<<"Operations on Heap"<<endl;
cout<<"------------------"<<endl;
cout<<"1.Insert Element"<<endl;
cout<<"2.Delete Minimum Element"<<endl;
cout<<"3.Extract Minimum Element"<<endl;
cout<<"4.Print Heap"<<endl;
cout<<"5.Exit"<<endl;
int choice, element;
cout<<"Enter your choice: ";
cin>>choice;
switch(choice)
{
case 1:
cout<<"Enter the element to be inserted: ";
cin>>element;
h.Insert(element);
break;
case 2:
h.DeleteMin();
break;
case 3:
cout<<"Minimum Element: ";
if (h.ExtractMin() == -1)
{
cout<<"Heap is Empty"<<endl;
}
else
cout<<"Minimum Element: "<<h.ExtractMin()<<endl;
break;
case 4:
cout<<"Displaying elements of Hwap: ";
h.DisplayHeap();
break;
case 5:
exit(1);
default:
cout<<"Enter Correct Choice"<<endl;
}
}
return 0;
}Sample Output:
------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 7 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 7 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 4 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 4 7 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 9 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 4 7 9 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 3 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 3 4 9 7 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 3 Minimum Element: Minimum Element: 3 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 5 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 3 4 9 7 5 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 11 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 3 4 9 7 5 11 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 1 Enter the element to be inserted: 2 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 2 4 3 7 5 11 9 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 2 Element Deleted ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 3 4 11 7 5 9 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 3 Minimum Element: Minimum Element: 3 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 2 Element Deleted ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 4 Displaying elements of Hwap: Heap --> 4 5 11 7 9 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 3 Minimum Element: Minimum Element: 4 ------------------ Operations on Heap ------------------ 1.Insert Element 2.Delete Minimum Element 3.Extract Minimum Element 4.Print Heap 5.Exit Enter your choice: 5 ------------------