Question

Implementing Polynomials using Singly Linked List in C++

Answer 1

Greetings!!!!

Please find the implementation of polynomial using singly linked list in c++ with a sample run screen shot.

#include <iostream>
#include <malloc.h>
#include<conio.h>
using namespace std;

//Node of the polynomial linked list is implemented by below structure
struct node
{
    int exponent;
    int cofficient;
    struct node *next;
};

//Initially set start pointer to point to the NULL
struct node *start=NULL;

// Function declaration to create polynomial.
struct node *create_Polynomial(struct node *);

// Function declaration to display polynomial.
struct node *display_Polynomial(struct node *);


int main()
{
    // choice is read by user for creation of polynomial, display of polynomial, and exit from program.
    int choice;
    
    do
    {
        //Display the menu for polynomial.
        cout<<"\n\n\nmain menu";
        cout<<"\n1.Enter the polynomial";
        cout<<"\n2.Display the polynomial";
        cout<<"\n3.Exit";
        
        //Take input as choice for creation of polynomial, display of polynomial, and exit from program
        cout<<"\nEnter Your Choice: ";
        cin>>choice;
        
        switch(choice)
        {
            case 1:
                start=create_Polynomial(start);
                cout<<"\n Polynomial Created Successfully!!! \n";
                break;
            case 2:
                cout<<"\nPolynomial is displayed as below:\n";
                start=display_Polynomial(start);
        }
    }while(choice!=3);
    
    getch();
    return 0;
}

// Function to create polynomial.
struct node *create_Polynomial(struct node *start)
{
    cout<<"\n Enter exponent value in descending order"; 
    struct node *newNode,*ptr;
    int exponent,cofficient;
    cout<<"\nEnter the exponent: ";
    cin>>exponent;
    cout<<"\nEnter its cofficient: ";
    cin>>cofficient;
    
    while (exponent!=-1)
    {
        //Create new Node of polynomial
        newNode=new struct node();
        
        //Assigning cofficient and exponent to the term.
        newNode->exponent= exponent;
        newNode->cofficient= cofficient;
        
        // Setting last node to point to the NULL.
        newNode->next=NULL;
        
        //Check if it is first node of polynomial 
        if (start==NULL)
        {
            start=newNode;
        }
        else
        {
            ptr=start;
            while(ptr->next!=NULL)
            {
               ptr=ptr->next; 
            }
            
            //Adding new node to the last of linked list.
            ptr->next=newNode;
        }
        
        //Take input as exponent
        cout<<"\n Enter exponent or -1 to stop crating polynomial: ";
        cin>>exponent;
        
        //Check for -1, if wanted to end with cration of polynomial
        if (exponent==-1)
            break;
            
        //Take input as cofficient.    
        cout<<"\n Enter its cofficient: ";
        cin>>cofficient;
    }
    return start;
}


// Function to display polynomial
struct node *display_Polynomial(struct node *start)
{
    //Loop every term (Node) of polynomial.
    while(start!=NULL)
    {
        if(start->exponent!=0)
        {
            if(start->cofficient<0)
                cout<<start->cofficient<<"x^"<<start->exponent;
            else
                cout<<"+"<<start->cofficient<<"x^"<<start->exponent;
        }
        else
        {
            if(start->cofficient<0)
                cout<<start->cofficient;
            else
                cout<<"+"<<start->cofficient;
        }
        start=start->next;
    }
    return start;
}

Thank You