C++ Program to Implement Binary Heap

A Binary Heap is a complete binary tree which is either Min Heap or Max Heap. In a Max Binary Heap, the key at root must be maximum among all keys present in Binary Heap. This property must be recursively true for all nodes in that Binary Tree. Min Binary Heap is similar to MinHeap.

Function descriptions:

void BHeap::Insert(int ele): Perform insertion operation to insert element in heap.

void BHeap::DeleteMin(): Perform deleteion operation to delete minimum value from heap.

int BHeap::ExtractMin(): Perfrom operation to extract minimum value from heap.

void BHeap::showHeap(): To show the elements of heap.

void BHeap::heapifyup(int in): maintain heap structure in bottom up manner.

void BHeap::heapifydown(int in): maintain heap structure in top down manner.

Example

#include 
#include 
#include 
#include 
using namespace std;
class BHeap {
   private:
   vector  heap;
   int l(int parent);
   int r(int parent);
   int par(int child);
   void heapifyup(int index);
   void heapifydown(int index);
   public:
      BHeap() {}
      void Insert(int element);
      void DeleteMin();
      int ExtractMin();
      void showHeap();
      int Size();
};
int main() {
   BHeap h;
   while (1) {
      cout<<"1.Insert Element"<>c;
      switch(c) {
         case 1:
            cout<<"Enter the element to be inserted: ";
            cin>>e;
            h.Insert(e);
         break;
         case 2:
            h.DeleteMin();
         break;
         case 3:
            if (h.ExtractMin() == -1) {
               cout<<"Heap is Empty"<::iterator pos = heap.begin();
   cout<<"Heap --> ";
   while (pos != heap.end()) {
      cout<<*pos<<" ";
      pos++;
   }
   cout<= 0 && par(in) >= 0 && heap[par(in)] > heap[in]) {
      int temp = heap[in];
      heap[in] = heap[par(in)];
      heap[par(in)] = temp;
      heapifyup(par(in));
   }
}
void BHeap::heapifydown(int in) {
   int child = l(in);
   int child1 = r(in);
   if (child >= 0 && child1 >= 0 && heap[child] > heap[child1]) {
      child = child1;
   }
   if (child > 0 && heap[in] > heap[child]) {
      int t = heap[in];
      heap[in] = heap[child];
      heap[child] = t;
      heapifydown(child);
   }
}

Output

1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 1
Enter the element to be inserted: 2
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 1
Enter the element to be inserted: 3
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 1
Enter the element to be inserted: 7
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 1
Enter the element to be inserted: 6
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 4
Displaying elements of Hwap: Heap --> 2 3 7 6
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 3
Minimum Element: 2
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 3
Minimum Element: 2
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 2
Element Deleted
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 4
Displaying elements of Hwap: Heap --> 3 6 7
1.Insert Element
2.Delete Minimum Element
3.Extract Minimum Element
4.Show Heap
5.Exit
Enter your choice: 5