Method Decrease_key

16. Heap/FibonacciHeap.cpp:286–318

Decrease Key Operation

// Decrease Key Operation
int FibonacciHeap::Decrease_key(node *H1, int x, int k)
{
    node *y;
    if (H1 == NULL)
    {
        cout << "The Heap is Empty" << endl;
        return 0;
    }
    node *ptr = Find(H1, x);
    if (ptr == NULL)
    {
        cout << "Node not found in the Heap" << endl;
        return 1;
    }

    if (ptr->n < k)
    {
        cout << "Entered key greater than current key" << endl;
        return 0;
    }
    ptr->n = k;
    y = ptr->parent;
    if (y != NULL && ptr->n < y->n)
    {
        Cut(H1, ptr, y);
        Cascase_cut(H1, y);
    }

    if (ptr->n < H->n)
        H = ptr;

    return 0;
}

// Cutting Function
int FibonacciHeap::Cut(node *H1, node *x, node *y)