Polynomial:

package poly;

import java.io.IOException; import java.util.Scanner;

/** * This class implements evaluate, add and multiply for polynomials. * * @author runb-cs112 * */ public class Polynomial { /** * Reads a polynomial from an input stream (file or keyboard). The storage format * of the polynomial is: *

 *   *   * ... *   * 

* with the guarantee that degrees will be in descending order. For example: *

 * 4 5 * -2 3 * 2 1 * 3 0 * 

* which represents the polynomial: *

 * 4*x^5 - 2*x^3 + 2*x + 3 * 

* * @param sc Scanner from which a polynomial is to be read * @throws IOException If there is any input error in reading the polynomial * @return The polynomial linked list (front node) constructed from coefficients and * degrees read from scanner */ public static Node read(Scanner sc) throws IOException { Node poly = null; while (sc.hasNextLine()) { Scanner scLine = new Scanner(sc.nextLine()); poly = new Node(scLine.nextFloat(), scLine.nextInt(), poly); scLine.close(); } return poly; } /** * Returns the sum of two polynomials - DOES NOT change either of the input polynomials. * The returned polynomial MUST have all new nodes. In other words, none of the nodes * of the input polynomials can be in the result. * * @param poly1 First input polynomial (front of polynomial linked list) * @param poly2 Second input polynomial (front of polynomial linked list * @return A new polynomial which is the sum of the input polynomials - the returned node * is the front of the result polynomial */ public static Node add(Node poly1, Node poly2) { /** COMPLETE THIS METHOD **/ // FOLLOWING LINE IS A PLACEHOLDER TO MAKE THIS METHOD COMPILE // CHANGE IT AS NEEDED FOR YOUR IMPLEMENTATION return null; } /** * Returns the product of two polynomials - DOES NOT change either of the input polynomials. * The returned polynomial MUST have all new nodes. In other words, none of the nodes * of the input polynomials can be in the result. * * @param poly1 First input polynomial (front of polynomial linked list) * @param poly2 Second input polynomial (front of polynomial linked list) * @return A new polynomial which is the product of the input polynomials - the returned node * is the front of the result polynomial */ public static Node multiply(Node poly1, Node poly2) { /** COMPLETE THIS METHOD **/ // FOLLOWING LINE IS A PLACEHOLDER TO MAKE THIS METHOD COMPILE // CHANGE IT AS NEEDED FOR YOUR IMPLEMENTATION return null; } /** * Evaluates a polynomial at a given value. * * @param poly Polynomial (front of linked list) to be evaluated * @param x Value at which evaluation is to be done * @return Value of polynomial p at x */ public static float evaluate(Node poly, float x) { /** COMPLETE THIS METHOD **/ // FOLLOWING LINE IS A PLACEHOLDER TO MAKE THIS METHOD COMPILE // CHANGE IT AS NEEDED FOR YOUR IMPLEMENTATION return 0; } /** * Returns string representation of a polynomial * * @param poly Polynomial (front of linked list) * @return String representation, in descending order of degrees */ public static String toString(Node poly) { if (poly == null) { return "0"; } String retval = poly.term.toString(); for (Node current = poly.next ; current != null ; current = current.next) { retval = current.term.toString() + " + " + retval; } return retval; } }