Open In App
Related Articles

Implementation of Binomial Heap | Set – 2 (delete() and decreseKey())

Improve
Improve
Improve
Like Article
Like
Save Article
Save
Report issue
Report

In previous post i.e. Set 1 we have discussed that implements these below functions:

  1. insert(H, k): Inserts a key ‘k’ to Binomial Heap ‘H’. This operation first creates a Binomial Heap with single key ‘k’, then calls union on H and the new Binomial heap.
  2. getMin(H): A simple way to getMin() is to traverse the list of root of Binomial Trees and return the minimum key. This implementation requires O(Logn) time. It can be optimized to O(1) by maintaining a pointer to minimum key root.
  3. extractMin(H): This operation also uses union(). We first call getMin() to find the minimum key Binomial Tree, then we remove the node and create a new Binomial Heap by connecting all subtrees of the removed minimum node. Finally we call union() on H and the newly created Binomial Heap. This operation requires O(Logn) time.

Examples:

12------------10--------------------20
/ \ / | \
15 50 70 50 40
| / | |
30 80 85 65
|
100
A Binomial Heap with 13 nodes. It is a collection of 3
Binomial Trees of orders 0, 2 and 3 from left to right.
10--------------------20
/ \ / | \
15 50 70 50 40
| / | |
30 80 85 65
|
100

In this post, below functions are implemented.

  1. delete(H): Like Binary Heap, delete operation first reduces the key to minus infinite, then calls extractMin().
  2. decreaseKey(H): decreaseKey() is also similar to Binary Heap. We compare the decreases key with it parent and if parent’s key is more, we swap keys and recur for parent. We stop when we either reach a node whose parent has smaller key or we hit the root node. Time complexity of decreaseKey() is O(Logn)

Implementation:

C++

// C++ program for implementation of
// Binomial Heap and Operations on it
#include <bits/stdc++.h>
using namespace std;
 
// Structure of Node
struct Node {
    int val, degree;
    Node *parent, *child, *sibling;
};
 
// Making root global to avoid one extra
// parameter in all functions.
Node* root = NULL;
 
// link two heaps by making h1 a child
// of h2.
int binomialLink(Node* h1, Node* h2)
{
    h1->parent = h2;
    h1->sibling = h2->child;
    h2->child = h1;
    h2->degree = h2->degree + 1;
}
 
// create a Node
Node* createNode(int n)
{
    Node* new_node = new Node;
    new_node->val = n;
    new_node->parent = NULL;
    new_node->sibling = NULL;
    new_node->child = NULL;
    new_node->degree = 0;
    return new_node;
}
 
// This function merge two Binomial Trees
Node* mergeBHeaps(Node* h1, Node* h2)
{
    if (h1 == NULL)
        return h2;
    if (h2 == NULL)
        return h1;
 
    // define a Node
    Node* res = NULL;
 
    // check degree of both Node i.e.
    // which is greater or smaller
    if (h1->degree <= h2->degree)
        res = h1;
 
    else if (h1->degree > h2->degree)
        res = h2;
 
    // traverse till if any of heap gets empty
    while (h1 != NULL && h2 != NULL) {
        // if degree of h1 is smaller, increment h1
        if (h1->degree < h2->degree)
            h1 = h1->sibling;
 
        // Link h1 with h2 in case of equal degree
        else if (h1->degree == h2->degree) {
            Node* sib = h1->sibling;
            h1->sibling = h2;
            h1 = sib;
        }
 
        // if h2 is greater
        else {
            Node* sib = h2->sibling;
            h2->sibling = h1;
            h2 = sib;
        }
    }
    return res;
}
 
// This function perform union operation on two
// binomial heap i.e. h1 & h2
Node* unionBHeaps(Node* h1, Node* h2)
{
    if (h1 == NULL && h2 == NULL)
        return NULL;
 
    Node* res = mergeBHeaps(h1, h2);
 
    // Traverse the merged list and set
    // values according to the degree of
    // Nodes
    Node *prev = NULL, *curr = res, *next = curr->sibling;
    while (next != NULL) {
        if ((curr->degree != next->degree)
            || ((next->sibling != NULL)
                && (next->sibling)->degree
                       == curr->degree)) {
            prev = curr;
            curr = next;
        }
 
        else {
            if (curr->val <= next->val) {
                curr->sibling = next->sibling;
                binomialLink(next, curr);
            }
            else {
                if (prev == NULL)
                    res = next;
                else
                    prev->sibling = next;
                binomialLink(curr, next);
                curr = next;
            }
        }
        next = curr->sibling;
    }
    return res;
}
 
// Function to insert a Node
void binomialHeapInsert(int x)
{
    // Create a new node and do union of
    // this node with root
    root = unionBHeaps(root, createNode(x));
}
 
// Function to display the Nodes
void display(Node* h)
{
    while (h) {
        cout << h->val << " ";
        display(h->child);
        h = h->sibling;
    }
}
 
// Function to reverse a list
// using recursion.
int revertList(Node* h)
{
    if (h->sibling != NULL) {
        revertList(h->sibling);
        (h->sibling)->sibling = h;
    }
    else
        root = h;
}
 
// Function to extract minimum value
Node* extractMinBHeap(Node* h)
{
    if (h == NULL)
        return NULL;
 
    Node* min_node_prev = NULL;
    Node* min_node = h;
 
    // Find minimum value
    int min = h->val;
    Node* curr = h;
    while (curr->sibling != NULL) {
        if ((curr->sibling)->val < min) {
            min = (curr->sibling)->val;
            min_node_prev = curr;
            min_node = curr->sibling;
        }
        curr = curr->sibling;
    }
 
    // If there is a single Node
    if (min_node_prev == NULL && min_node->sibling == NULL)
        h = NULL;
 
    else if (min_node_prev == NULL)
        h = min_node->sibling;
 
    // Remove min node from list
    else
        min_node_prev->sibling = min_node->sibling;
 
    // Set root (which is global) as children
    // list of min node
    if (min_node->child != NULL) {
        revertList(min_node->child);
        (min_node->child)->sibling = NULL;
    }
    else
        root = NULL;
      delete min_node;
    // Do union of root h and children
    return unionBHeaps(h, root);
}
 
// Function to search for an element
Node* findNode(Node* h, int val)
{
    if (h == NULL)
        return NULL;
 
    // check if key is equal to the root's data
    if (h->val == val)
        return h;
 
    // Recur for child
    Node* res = findNode(h->child, val);
    if (res != NULL)
        return res;
 
    return findNode(h->sibling, val);
}
 
// Function to decrease the value of old_val
// to new_val
void decreaseKeyBHeap(Node* H, int old_val, int new_val)
{
    // First check element present or not
    Node* node = findNode(H, old_val);
 
    // return if Node is not present
    if (node == NULL)
        return;
 
    // Reduce the value to the minimum
    node->val = new_val;
    Node* parent = node->parent;
 
    // Update the heap according to reduced value
    while (parent != NULL && node->val < parent->val) {
        swap(node->val, parent->val);
        node = parent;
        parent = parent->parent;
    }
}
 
// Function to delete an element
Node* binomialHeapDelete(Node* h, int val)
{
    // Check if heap is empty or not
    if (h == NULL)
        return NULL;
 
    // Reduce the value of element to minimum
    decreaseKeyBHeap(h, val, INT_MIN);
 
    // Delete the minimum element from heap
    return extractMinBHeap(h);
}
 
// Driver code
int main()
{
    // Note that root is global
    binomialHeapInsert(10);
    binomialHeapInsert(20);
    binomialHeapInsert(30);
    binomialHeapInsert(40);
    binomialHeapInsert(50);
 
    cout << "The heap is:\n";
    display(root);
 
    // Delete a particular element from heap
    root = binomialHeapDelete(root, 10);
 
    cout << "\nAfter deleting 10, the heap is:\n";
 
    display(root);
 
    return 0;
}

                    

Java

import java.util.ArrayList;
import java.util.List;
 
// Structure of Node
class Node {
    int val, degree;
    Node parent, child, sibling;
}
 
// Class to represent a Binomial Heap
class BinomialHeap {
    private Node root;
 
    // Making root global to avoid one extra parameter in all functions.
    public BinomialHeap() {
        this.root = null;
    }
 
    // Link two heaps by making h1 a child of h2.
    private void binomialLink(Node h1, Node h2) {
        h1.parent = h2;
        h1.sibling = h2.child;
        h2.child = h1;
        h2.degree = h2.degree + 1;
    }
 
    // Create a Node
    private Node createNode(int n) {
        Node new_node = new Node();
        new_node.val = n;
        new_node.parent = null;
        new_node.sibling = null;
        new_node.child = null;
        new_node.degree = 0;
        return new_node;
    }
 
    // This function merge two Binomial Trees
    private Node mergeBHeaps(Node h1, Node h2) {
        if (h1 == null)
            return h2;
        if (h2 == null)
            return h1;
 
        // Define a Node
        Node res;
 
        // Check degree of both Node i.e. which is greater or smaller
        if (h1.degree <= h2.degree)
            res = h1;
        else
            res = h2;
 
        // Traverse till if any of the heap gets empty
        while (h1 != null && h2 != null) {
            // If degree of h1 is smaller, increment h1
            if (h1.degree < h2.degree)
                h1 = h1.sibling;
 
            // Link h1 with h2 in case of equal degree
            else if (h1.degree == h2.degree) {
                Node sib = h1.sibling;
                h1.sibling = h2;
                h1 = sib;
            }
 
            // If h2 is greater
            else {
                Node sib = h2.sibling;
                h2.sibling = h1;
                h2 = sib;
            }
        }
        return res;
    }
 
    // This function performs the union operation on two binomial heaps i.e. h1 & h2
    private Node unionBHeaps(Node h1, Node h2) {
        if (h1 == null && h2 == null)
            return null;
 
        Node res = mergeBHeaps(h1, h2);
 
        // Traverse the merged list and set values according to the degree of Nodes
        Node prev = null, curr = res, next = curr.sibling;
        while (next != null) {
            if ((curr.degree != next.degree) || ((next.sibling != null) && (next.sibling).degree == curr.degree)) {
                prev = curr;
                curr = next;
            } else {
                if (curr.val <= next.val) {
                    curr.sibling = next.sibling;
                    binomialLink(next, curr);
                } else {
                    if (prev == null)
                        res = next;
                    else
                        prev.sibling = next;
                    binomialLink(curr, next);
                    curr = next;
                }
            }
            next = curr.sibling;
        }
        return res;
    }
 
    // Function to insert a Node
    public void binomialHeapInsert(int x) {
        // Create a new node and do union of this node with root
        root = unionBHeaps(root, createNode(x));
    }
 
    // Function to display the Nodes
    private void display(Node h) {
        while (h != null) {
            System.out.print(h.val + " ");
            display(h.child);
            h = h.sibling;
        }
    }
 
    // Function to reverse a list using recursion.
    private Node revertList(Node h) {
        if (h.sibling != null) {
            revertList(h.sibling);
            (h.sibling).sibling = h;
        } else
            root = h;
        return root;
    }
 
    // Function to extract the minimum value
    private Node extractMinBHeap(Node h) {
        if (h == null)
            return null;
 
        Node min_node_prev = null;
        Node min_node = h;
 
        // Find the minimum value
        int min = h.val;
        Node curr = h;
        while (curr.sibling != null) {
            if ((curr.sibling).val < min) {
                min = (curr.sibling).val;
                min_node_prev = curr;
                min_node = curr.sibling;
            }
            curr = curr.sibling;
        }
 
        // If there is a single Node
        if (min_node_prev == null && min_node.sibling == null)
            h = null;
 
        else if (min_node_prev == null)
            h = min_node.sibling;
 
        // Remove the min node from the list
        else
            min_node_prev.sibling = min_node.sibling;
 
        // Set root (which is global) as children list of min node
        if (min_node.child != null) {
            revertList(min_node.child);
            (min_node.child).sibling = null;
        } else
            root = null;
 
        return unionBHeaps(h, root);
    }
 
    // Function to search for an element
    private Node findNode(Node h, int val) {
        if (h == null)
            return null;
 
        // Check if key is equal to the root's data
        if (h.val == val)
            return h;
 
        // Recur for child
        Node res = findNode(h.child, val);
        if (res != null)
            return res;
 
        return findNode(h.sibling, val);
    }
 
    // Function to decrease the value of old_val to new_val
    private void decreaseKeyBHeap(Node H, int old_val, int new_val) {
        // First check if the Node is present
        Node node = findNode(H, old_val);
 
        // Return if Node is not present
        if (node == null)
            return;
 
        // Reduce the value to the minimum
        node.val = new_val;
        Node parent = node.parent;
 
        // Update the heap according to the reduced value
        while (parent != null && node.val < parent.val) {
            int temp = node.val;
            node.val = parent.val;
            parent.val = temp;
            node = parent;
            parent = parent.parent;
        }
    }
 
    // Function to delete an element
    public void binomialHeapDelete(int val) {
        // Check if the heap is empty or not
        if (root == null)
            return;
 
        // Reduce the value of element to minimum
        decreaseKeyBHeap(root, val, Integer.MIN_VALUE);
 
        // Delete the minimum element from the heap
        root = extractMinBHeap(root);
    }
 
    // Driver code
    public static void main(String[] args) {
        BinomialHeap heap = new BinomialHeap();
        heap.binomialHeapInsert(10);
        heap.binomialHeapInsert(20);
        heap.binomialHeapInsert(30);
        heap.binomialHeapInsert(40);
        heap.binomialHeapInsert(50);
 
        System.out.println("The heap is:");
        heap.display(heap.root);
 
        // Delete a particular element from the heap
        heap.binomialHeapDelete(10);
 
        System.out.println("\nAfter deleting 10, the heap is:");
        heap.display(heap.root);
    }
}

                    

Python3

# python program for implementation of
# Binomial Heap and Operations on it
 
INT_MIN = -2147483648;
g = 0
# Structure of Node
class Node:
     
    def __init__(self):
        self.val = 0;
        self.degree = 0;
        self.parent = None;
        self.child = None;
        self.sibling = None;
 
 
# Making root global to avoid one extra
# parameter in all functions.
root = None;
 
# link two heaps by making h1 a child
# of h2.
def binomialLink(h1, h2):
    h1.parent = h2;
    h1.sibling = h2.child;
    h2.child = h1;
    h2.degree = h2.degree + 1;
     
    return -1;
 
# create a Node
def createNode(n):
    new_node = Node();
    new_node.val = n;
    new_node.parent = None;
    new_node.sibling = None;
    new_node.child = None;
    new_node.degree = 0;
    return new_node;
 
# This function merge two Binomial Trees
def mergeBHeaps(h1, h2):
    if (h1 == None):
        return h2;
    if (h2 == None):
        return h1;
 
    # define a Node
    res = None;
 
    # check degree of both Node i.e.
    # which is greater or smaller
    if (h1.degree <= h2.degree):
        res = h1;
 
    elif(h1.degree > h2.degree):
        res = h2;
 
    # traverse till if any of heap gets empty
    while (h1 != None and h2 != None):
        # if degree of h1 is smaller, increment h1
        if (h1.degree < h2.degree):
            h1 = h1.sibling;
 
        # Link h1 with h2 in case of equal degree
        elif(h1.degree == h2.degree):
            sib = h1.sibling;
            h1.sibling = h2;
            h1 = sib;
 
        # if h2 is greater
        else:
            sib = h2.sibling;
            h2.sibling = h1;
            h2 = sib;
    return res;
 
 
# This function perform union operation on two
# binomial heap i.e. h1 & h2
def unionBHeaps(h1,  h2):
    # global root
    if (h1 == None and h2 == None):
        return None;
 
    res = mergeBHeaps(h1, h2);
 
    # Traverse the merged list and set
    # values according to the degree of
    # Nodes
    prev = None;
    curr = res;
    next = curr.sibling;
    while (next != None):
        if ((curr.degree != next.degree) or ((next.sibling != None) and (next.sibling).degree == curr.degree)):
            prev = curr;
            curr = next;
 
        else:
            if (curr.val <= next.val):
                curr.sibling = next.sibling;
                binomialLink(next, curr);
            else:
                if (prev == None):
                    res = next;
                else:
                    prev.sibling = next;
                binomialLink(curr, next);
                curr = next;
 
        next = curr.sibling;
    return res;
 
# Function to insert a Node
def binomialHeapInsert(x):
    # Create a new node and do union of
    # this node with root
    global root
    root = unionBHeaps(root, createNode(x));
     
 
# Function to display the Nodes
def display(h):
     
    global g
     
    while (h):
 
        if g != 1 or h.val != 10:
            print(h.val,end =  " ");
        display(h.child);
        h = h.sibling;
 
# Function to reverse a list
# using recursion.
def revertList(h):
    if (h.sibling != None):
        revertList(h.sibling);
        (h.sibling).sibling = h;
 
    else:
        root = h;
     
    return -1;
 
# Function to extract minimum value
def extractMinBHeap(h):
    global root
    if (h == None):
        return None;
 
    min_node_prev = None;
    min_node = h;
 
    # Find minimum value
    min = h.val;
    curr = h;
    while (curr.sibling != None):
        if ((curr.sibling).val < min):
            min = (curr.sibling).val;
            min_node_prev = curr;
            min_node = curr.sibling;
 
        curr = curr.sibling;
 
 
    # If there is a single Node
    if (min_node_prev == None and min_node.sibling == None):
        h = None;
 
    elif(min_node_prev == None):
        h = min_node.sibling;
 
    # Remove min node from list
    else:
        min_node_prev.sibling = min_node.sibling;
 
    # Set root (which is global) as children
    # list of min node
    if (min_node.child != None):
        revertList(min_node.child);
        (min_node.child).sibling = None;
 
    else:
        root = None;
    del min_node;
     
    # Do union of root h and children
    return unionBHeaps(h, root);
 
# Function to search for an element
def findNode( h, val):
 
    if (h == None):
        return None;
 
    # check if key is equal to the root's data
    if (h.val == val):
        return h;
 
    # Recur for child
    res = findNode(h.child, val);
    if (res != None):
        return res;
 
    return findNode(h.sibling, val);
 
 
# Function to decrease the value of old_val
# to new_val
def decreaseKeyBHeap(H, old_val, new_val):
 
    # First check element present or not
    node = findNode(H, old_val);
 
    # return if Node is not present
    if (node == None):
        return;
 
    # Reduce the value to the minimum
    node.val = new_val;
    parent = node.parent;
 
    # Update the heap according to reduced value
    while (parent != None and node.val < parent.val):
        temp = node.val;
        node.val = parent.val;
        parent.val = temp;
        node = parent;
        parent = parent.parent;
 
# Function to delete an element
def binomialHeapDelete( h, val):
     
    global root;
    return root;
 
    # Check if heap is empty or not
    if (h == None):
        return  None;
 
    # Reduce the value of element to minimum
    decreaseKeyBHeap(h, val, INT_MIN);
 
    # Delete the minimum element from heap
    return extractMinBHeap(h);
 
#Driver code
 
#Note that root is global
binomialHeapInsert(10);
binomialHeapInsert(20);
binomialHeapInsert(30);
binomialHeapInsert(40);
binomialHeapInsert(50);
 
print("The heap is:");
display(root);
 
#Delete a particular element from heap
root = binomialHeapDelete(root, 10);
 
print("\nAfter deleting 10, the heap is:");
 
# stores bool
g = 1
 
# display
display(root);
 
#The code is contributed by Nidhi goel.

                    

C#

using System;
 
class BinomialHeap {
    class Node {
        public int val, degree;
        public Node parent, child, sibling;
    }
 
    static Node root = null;
 
    static int BinomialLink(Node h1, Node h2)
    {
        h1.parent = h2;
        h1.sibling = h2.child;
        h2.child = h1;
        h2.degree = h2.degree + 1;
        return 0;
    }
 
    static Node CreateNode(int n)
    {
        Node newNode = new Node();
        newNode.val = n;
        newNode.parent = null;
        newNode.sibling = null;
        newNode.child = null;
        newNode.degree = 0;
        return newNode;
    }
 
    static Node MergeBHeaps(Node h1, Node h2)
    {
        if (h1 == null)
            return h2;
        if (h2 == null)
            return h1;
 
        Node res = null;
 
        if (h1.degree <= h2.degree)
            res = h1;
        else if (h1.degree > h2.degree)
            res = h2;
 
        while (h1 != null && h2 != null) {
            if (h1.degree < h2.degree)
                h1 = h1.sibling;
            else if (h1.degree == h2.degree) {
                Node sib = h1.sibling;
                h1.sibling = h2;
                h1 = sib;
            }
            else {
                Node sib = h2.sibling;
                h2.sibling = h1;
                h2 = sib;
            }
        }
        return res;
    }
 
    static Node UnionBHeaps(Node h1, Node h2)
    {
        if (h1 == null && h2 == null)
            return null;
 
        Node res = MergeBHeaps(h1, h2);
 
        Node prev = null, curr = res, next = curr.sibling;
        while (next != null) {
            if ((curr.degree != next.degree)
                || ((next.sibling != null)
                    && (next.sibling).degree
                           == curr.degree)) {
                prev = curr;
                curr = next;
            }
            else {
                if (curr.val <= next.val) {
                    curr.sibling = next.sibling;
                    BinomialLink(next, curr);
                }
                else {
                    if (prev == null)
                        res = next;
                    else
                        prev.sibling = next;
                    BinomialLink(curr, next);
                    curr = next;
                }
            }
            next = curr.sibling;
        }
        return res;
    }
 
    static void BinomialHeapInsert(int x)
    {
        root = UnionBHeaps(root, CreateNode(x));
    }
 
    static void Display(Node h)
    {
        while (h != null) {
            Console.Write(h.val + " ");
            Display(h.child);
            h = h.sibling;
        }
    }
 
    static int RevertList(Node h)
    {
        if (h.sibling != null) {
            RevertList(h.sibling);
            (h.sibling).sibling = h;
        }
        else
            root = h;
        return 0;
    }
 
    static Node ExtractMinBHeap(Node h)
    {
        if (h == null)
            return null;
 
        Node minNodePrev = null;
        Node minNode = h;
 
        int min = h.val;
        Node curr = h;
        while (curr.sibling != null) {
            if ((curr.sibling).val < min) {
                min = (curr.sibling).val;
                minNodePrev = curr;
                minNode = curr.sibling;
            }
            curr = curr.sibling;
        }
 
        if (minNodePrev == null && minNode.sibling == null)
            h = null;
        else if (minNodePrev == null)
            h = minNode.sibling;
        else
            minNodePrev.sibling = minNode.sibling;
 
        if (minNode.child != null) {
            RevertList(minNode.child);
            (minNode.child).sibling = null;
        }
        else
            root = null;
 
        // Delete minNode to avoid memory leak
        minNode = null;
 
        return UnionBHeaps(h, root);
    }
 
    static Node FindNode(Node h, int val)
    {
        if (h == null)
            return null;
 
        if (h.val == val)
            return h;
 
        Node res = FindNode(h.child, val);
        if (res != null)
            return res;
 
        return FindNode(h.sibling, val);
    }
 
    static void DecreaseKeyBHeap(Node H, int oldVal,
                                 int newVal)
    {
        Node node = FindNode(H, oldVal);
 
        if (node == null)
            return;
 
        node.val = newVal;
        Node parent = node.parent;
 
        while (parent != null && node.val < parent.val) {
            Swap(ref node.val, ref parent.val);
            node = parent;
            parent = parent.parent;
        }
    }
 
    static Node BinomialHeapDelete(Node h, int val)
    {
        if (h == null)
            return null;
 
        DecreaseKeyBHeap(h, val, int.MinValue);
 
        return ExtractMinBHeap(h);
    }
 
    static void Swap(ref int a, ref int b)
    {
        int temp = a;
        a = b;
        b = temp;
    }
 
    static void Main()
    {
        BinomialHeapInsert(10);
        BinomialHeapInsert(20);
        BinomialHeapInsert(30);
        BinomialHeapInsert(40);
        BinomialHeapInsert(50);
 
        Console.WriteLine("The heap is:");
        Display(root);
 
        root = BinomialHeapDelete(root, 10);
 
        Console.WriteLine(
            "\nAfter deleting 10, the heap is:");
        Display(root);
    }
}

                    

Javascript

// javascript program for implementation of
// Binomial Heap and Operations on it
 
const INT_MIN = -2147483648;
 
// Structure of Node
class Node {
     
    constructor(){
        this.val = 0;
        this.degree = 0;
        this.parent = null;
        this.child = null;
        this.sibling = null;
    }
}
 
// Making root global to avoid one extra
// parameter in all functions.
let root = null;
 
// link two heaps by making h1 a child
// of h2.
function binomialLink(h1, h2)
{
    h1.parent = h2;
    h1.sibling = h2.child;
    h2.child = h1;
    h2.degree = h2.degree + 1;
     
    return -1;
}
 
// create a Node
function createNode(n)
{
    let new_node = new Node;
    new_node.val = n;
    new_node.parent = null;
    new_node.sibling = null;
    new_node.child = null;
    new_node.degree = 0;
    return new_node;
}
 
// This function merge two Binomial Trees
function mergeBHeaps(h1, h2)
{
    if (h1 == null)
        return h2;
    if (h2 == null)
        return h1;
 
    // define a Node
    let res = null;
 
    // check degree of both Node i.e.
    // which is greater or smaller
    if (h1.degree <= h2.degree)
        res = h1;
 
    else if (h1.degree > h2.degree)
        res = h2;
 
    // traverse till if any of heap gets empty
    while (h1 != null && h2 != null) {
        // if degree of h1 is smaller, increment h1
        if (h1.degree < h2.degree)
            h1 = h1.sibling;
 
        // Link h1 with h2 in case of equal degree
        else if (h1.degree == h2.degree) {
            let sib = h1.sibling;
            h1.sibling = h2;
            h1 = sib;
        }
 
        // if h2 is greater
        else {
            let sib = h2.sibling;
            h2.sibling = h1;
            h2 = sib;
        }
    }
    return res;
}
 
// This function perform union operation on two
// binomial heap i.e. h1 & h2
function unionBHeaps(h1,  h2)
{
    if (h1 == null && h2 == null)
        return null;
 
    let res = mergeBHeaps(h1, h2);
 
    // Traverse the merged list and set
    // values according to the degree of
    // Nodes
    let prev = null;
    let curr = res;
    let next = curr.sibling;
    while (next != null) {
        if ((curr.degree != next.degree)
            || ((next.sibling != null)
                && (next.sibling).degree
                       == curr.degree)) {
            prev = curr;
            curr = next;
        }
 
        else {
            if (curr.val <= next.val) {
                curr.sibling = next.sibling;
                binomialLink(next, curr);
            }
            else {
                if (prev == null)
                    res = next;
                else
                    prev.sibling = next;
                binomialLink(curr, next);
                curr = next;
            }
        }
        next = curr.sibling;
    }
    return res;
}
 
// Function to insert a Node
function binomialHeapInsert(x)
{
    // Create a new node and do union of
    // this node with root
    root = unionBHeaps(root, createNode(x));
}
 
// Function to display the Nodes
function display(h)
{
    while (h) {
        process.stdout.write(h.val + " ");
        display(h.child);
        h = h.sibling;
    }
}
 
// Function to reverse a list
// using recursion.
function revertList(h)
{
    if (h.sibling != null) {
        revertList(h.sibling);
        (h.sibling).sibling = h;
    }
    else
        root = h;
     
    return -1;
}
 
// Function to extract minimum value
function extractMinBHeap(h)
{
    if (h == null)
        return null;
 
    let min_node_prev = null;
    let min_node = h;
 
    // Find minimum value
    let min = h.val;
    let curr = h;
    while (curr.sibling != null) {
        if ((curr.sibling).val < min) {
            min = (curr.sibling).val;
            min_node_prev = curr;
            min_node = curr.sibling;
        }
        curr = curr.sibling;
    }
 
    // If there is a single Node
    if (min_node_prev == null && min_node.sibling == null)
        h = null;
 
    else if (min_node_prev == null)
        h = min_node.sibling;
 
    // Remove min node from list
    else
        min_node_prev.sibling = min_node.sibling;
 
    // Set root (which is global) as children
    // list of min node
    if (min_node.child != null) {
        revertList(min_node.child);
        (min_node.child).sibling = null;
    }
    else
        root = null;
      delete min_node;
    // Do union of root h and children
    return unionBHeaps(h, root);
}
 
// Function to search for an element
function findNode( h, val)
{
    if (h == null)
        return null;
 
    // check if key is equal to the root's data
    if (h.val == val)
        return h;
 
    // Recur for child
    let res = findNode(h.child, val);
    if (res != null)
        return res;
 
    return findNode(h.sibling, val);
}
 
// Function to decrease the value of old_val
// to new_val
function decreaseKeyBHeap(H, old_val, new_val)
{
    // First check element present or not
    let node = findNode(H, old_val);
 
    // return if Node is not present
    if (node == null)
        return;
 
    // Reduce the value to the minimum
    node.val = new_val;
    let parent = node.parent;
 
    // Update the heap according to reduced value
    while (parent != null && node.val < parent.val) {
        let temp = node.val;
        node.val = parent.val;
        parent.val = temp;
        node = parent;
        parent = parent.parent;
    }
}
 
// Function to delete an element
function binomialHeapDelete( h, val)
{
    // Check if heap is empty or not
    if (h == null)
        return  null;
 
    // Reduce the value of element to minimum
    decreaseKeyBHeap(h, val, INT_MIN);
 
    // Delete the minimum element from heap
    return extractMinBHeap(h);
}
 
// Driver code
 
// Note that root is global
binomialHeapInsert(10);
binomialHeapInsert(20);
binomialHeapInsert(30);
binomialHeapInsert(40);
binomialHeapInsert(50);
 
console.log("The heap is:");
display(root);
 
// Delete a particular element from heap
root = binomialHeapDelete(root, 10);
 
console.log("\nAfter deleting 10, the heap is:");
 
display(root);
 
//The code is contributed by Nidhi goel.

                    

Output
The heap is:
50 10 30 40 20 
After deleting 10, the heap is:
20 30 40 50 


Last Updated : 18 Jan, 2024
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads