I know this works but I want to improve this code! I don't expect anyone to re-write this but if you have some "try this instead" then great!
import java.util.*; public class Polynomial implements Iterable, Comparable < Comparatorcompare; private Term head = null; //A constructor that accepts a string that defines one polynomial in the same format //as provided in the input file. public Polynomial(String file) < Scanner scan = new Scanner(file); try< while(scan.hasNext())< addTerm(scan.nextDouble(), scan.nextInt()); >> catch (Exception ex) < System.out.println(ex.getLocalizedMessage()); throw new InvalidPolynomialSyntax("Error: Invalid Polynomial Syntax, check input"); >> public void addTerm(double coefficient, int exponent ) < if (exponent < 0)< throw new InvalidPolynomialSyntax("Error: Invalid Polynomial Syntax, Negative exponents, check input"); >Term current = head; if(current == null) < head = new Term(coefficient, exponent); head.next = null; >else < while(current.next != null)< current = current.next; >current.next = new Term(coefficient, exponent); > > /* * A compareTo method that compares two polynomials. If their highest exponents are the * same, their coefficients are compared. If two polynomials have the same highest order exponent with the * same coefficients the next highest exponent is examined, and so on. */ @Override public int compareTo(Polynomial otherPoly) < Term thisCurrent = this.head; Term otherCurrent = otherPoly.head; while (thisCurrent != null && otherCurrent != null)< //If the two polynomials have different highest //order exponents, the one with the highest exponent is the greatest. if (thisCurrent.getExponent() != otherCurrent.getExponent())< return thisCurrent.getExponent() - otherCurrent.getExponent(); >else if(thisCurrent.getCoefficient() != otherCurrent.getCoefficient()) < if(otherCurrent.getCoefficient()>thisCurrent.getCoefficient()) < return -1; >else if(otherCurrent.getCoefficient() < thisCurrent.getCoefficient())< return +1; >> thisCurrent = thisCurrent.getNext(); otherCurrent = otherCurrent.getNext(); >//if both are null they are equal if (thisCurrent == null && otherCurrent == null)< return 0; >//If two polynomials have the same highest order exponent with the //same coefficients the next highest exponent is examined, and so on. if (thisCurrent == null)< return -1; >else < return +1; >> //If the exponents are the same. public int compareExponents(Polynomial poly2) < Term thisPolyTerm = this.head; Term otherPolyTerm = poly2.head; while(thisPolyTerm != null && otherPolyTerm != null) < if (thisPolyTerm.getExponent() != otherPolyTerm.getExponent()) < return thisPolyTerm.getExponent() - otherPolyTerm.getExponent(); >else < thisPolyTerm = thisPolyTerm.getNext(); otherPolyTerm = otherPolyTerm.getNext(); >> if(thisPolyTerm == null && otherPolyTerm == null) < return 0; >if (otherPolyTerm == null) < return +1; >else < return -1; >> public Polynomial() < compare = (Polynomial poly1, Polynomial poly2) ->poly1.compareExponents(poly2); > public Polynomial(Comparator compare) < this.compare = compare; >@Override public Iterator iterator() < return new Iterator() < private Term current = getHead(); @Override public boolean hasNext() < return current != null && current.getNext() != null; >@Override public Term next() < Term data = current; current = current.next; return data; >>; > @Override public String toString() < StringBuilder expressionBuilder = new StringBuilder(); //first check head to avoid +1x^3 +3x^2 if (head.coefficient >0) < expressionBuilder.append(head.toString()); >else < expressionBuilder.append(" - ").append(head.toString()); >for(Term tmp = head.next; tmp != null; tmp = tmp.next) < if (tmp.coefficient < 0) < expressionBuilder.append(" - ").append(tmp.toString()); >else < expressionBuilder.append(" + ").append(tmp.toString()); >> return expressionBuilder.toString(); > static class Term < private double coefficient; private int exponent; private Term next; private Term(double c, int e) < coefficient = c; exponent = e; next = null; >private int getExponent() < return this.exponent; >private double getCoefficient() < return this.coefficient; >private Term getNext() < return next; >@Override public String toString() < String termString = String.format("%.1f", Math.abs(coefficient)); if (exponent == 0) < return termString; >else if(exponent == 1) < return termString + "x"; >else < return termString + "x^" + exponent; >> > private Term getHead() < return head; >> I don't think this part needs anything changed to it but open to suggestions(mainly providing this so the code compiles and runs) OrderedList.Java
import java.util.*; /* * The third class is OrderedList, which is a utility class * that contains two overloaded implementations */ public class OrderedList < //Both methods should be class (static) methods. //The first of the overloaded methods should accept a list //that contains elements that implement Comparable. public static > //two overloaded implementations of a method named checkSorted boolean checkSorted(List list) < boolean isSorted = true; for(int i = list.size()-1; i >0 ; i--) < T current = list.get(i); if(!checkSorted(list, current))< isSorted = false; >> return isSorted; > //The second should instead be supplied an additional //parameter that is an object of a class that implements //the Comparator interface private static > boolean checkSorted(List list, T current) < T currentValue = list.get(list.indexOf(current)); T nextValue = list.get(list.indexOf(current) - 1); if (nextValue != null) < return currentValue.compareTo(nextValue) >= 0; > return true; > > Please ignore my notes, ha ha Main.java
import javax.swing.*; import java.io.*; import java.util.*; public class Main < private static ListpolyList = new ArrayList<>(); public static void main(String[] args) < processPolyList(); >public static ArrayList fromFile() < //Create ArrayList and JFileChooser ArrayListexpressionList = new ArrayList<>(); JFileChooser chooser = new JFileChooser(); //Show directories and files chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES); //user's current directory chooser.setCurrentDirectory(new File(System.getProperty("user.dir"))); int response = chooser.showOpenDialog(null); if (response == JFileChooser.APPROVE_OPTION) < File file = chooser.getSelectedFile(); try < Scanner scan = new Scanner(file); if (file.isFile())< while (scan.hasNextLine())< String expression = scan.nextLine(); expressionList.add(expression); >> > catch (NoSuchElementException a) < JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),"File is empty!"); >catch(FileNotFoundException b) < JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),"404 File Not Found!"); >> return expressionList; > public static boolean checkWeakOrder( List polyList) < boolean isWeakOrder = true; Polynomial previous = polyList.get(polyList.size()-1); for(int i = polyList.size()-2; i >0; i--) < if (previous.compareExponents(polyList.get(i)) < 0)< isWeakOrder = false; >> return isWeakOrder; > public static void processPolyList() < try < ArrayLista = fromFile(); for (String element : a) < Polynomial p = new Polynomial(element); System.out.println(p); polyList.add(p); >> catch (InvalidPolynomialSyntax ex) < JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),ex.getMessage()); >System.out.println("This list is sorted by the strong order: " + OrderedList.checkSorted(polyList)); System.out.println("This list is sorted by the weak order: " + checkWeakOrder(polyList)); > > InvalidPolynomialSyntax.java
/* * The second class is InvalidPolynomialSyntax, which defines an * unchecked exception that contains a constructor that allows a * message to be supplied. It is thrown by the constructor of * the Polynomial class should the supplied string contain * coefficients or exponents of an improper type or should the * exponents fail to be listed in strictly descending order. */ public class InvalidPolynomialSyntax extends RuntimeException < InvalidPolynomialSyntax(String message)< super(message); >>