HELP ABOUT LINKLIST POLYNOMIAL

[wilson454]

Write your question here.
How to modify the addterm(), polynomial add()?

  
#ifndef POLYNOMIAL_H
#define POLYNOMIAL_H

#include "linkedListType.h"


class term
{
friend ostream& operator<<(ostream& osObject, term& t);

private:
double coef;
int exp;

public:
term(){
coef = 0;
exp =0;}

term(double c, int e){
coef =c;
exp =e;}

~term(){}

void setCoef(double c){coef = c;}
void setExp(int e){exp = e;}
// double getCoef(){return coef;}
// int getExp(){return exp;}

term(const term& other){
coef =other.coef;
exp = other.exp;}

// precondition: exp == other.exp
// the operation for *this + other

term operator+ (const term& other){
term add;
add.coef = coef + other.coef;
add.exp = other.exp;
return add;	
}

// precondition: exp == other.exp
// operation for *this - other

term operator- (const term& other){
term sub;
sub.coef = coef + other.coef;
sub.exp = other.exp;
return sub;	
}

bool operator!= (const term& other){
if(exp != other.exp)
return true;
else
return false;
}

bool operator== (const term& other){
if (exp = other.exp)
return true;
else
return false;
}

//print a term
void print(){
cout<<coef<<" x^ "<<exp;
}


};

ostream& operator<<(ostream& osObject, term& t)
{
osObject << "(" << t.coef << ", " << t.exp << ") ";
return osObject;
}

//###########################################################


class polynomial
{
private:
linkedListType<term> *poly;

public:
polynomial(){ //default constructor
poly = NULL;
}

~polynomial(){}



polynomial(const polynomial &other){ //copy constructor	
poly = other.poly;

}

const polynomial& operator= (const polynomial& other){
if(this != &other)
polynomial(other);
return *this;
}

//append a term to the polynomial

void addTerm(term item){




}

//print the polynomial
void print(){
cout<< endl;

cout<<" + ";
}

//return a new polynomial that is equal to *this + other
//the contents of this and other should not be modified
polynomial& add(polynomial& other){

return *this;

}

//return a new polynomial that is equal to *this - other
//the contents of this and other should not be modified
polynomial& sub(polynomial& other){

return *this;

}
};



#endif

ANOTHER CODE

#include "polynomial.h"
#include "linkedListType.h"
using namespace std;

void readPolynomial(string filename, polynomial& p)
{}

int main()
{


string file1 = "poly1.txt";
string file2 = "poly2.txt";

polynomial p1;
readPolynomial(file1, p1);
cout << "P1 : ";
p1.print();
cout << endl;

polynomial p2;
readPolynomial(file2, p2);
cout << "P2 : ";
p2.print();
cout << endl;


cout << "P3 = P1 + P2 : ";
polynomial p3 = p1.add(p2);
p3.print();
cout << endl;

cout << "P4 = P1 - P2 : ";
polynomial p4 = p1.sub(p2);
p4.print();
cout << endl;

cout << "P5 = P3 + P1 : ";
polynomial p5 = p3.add(p1);
p5.print();
cout << endl;


system("pause");
exit(0);
}

[ats15]

You would need to post linkedListType.h to get an exact answer. I will just make some assumptions about what you have in that file.

For addTerm:
1. I would add terms with 0 exponent first, then 1, 2, ...
2. I would keep pointers to the beginning of the list, the end, and the current element
3. Get to the beginning of the list and start looping through the list.
4. If the item you get is NULL (you input a coefficient for the first time, or you arrived at the end of the list), you just insert that term into the list
5. If the exponent of the current term in the iteration is equal to the exponent of the term you want to insert you just add the coefficients
6. If the exponent of the current term in your iteration is greater than for the term you want to insert, insert your term in the list and make the current term as the next one

For adding polynomials you use the same procedure, you just add a for loop over the first polynomial, to get the term to insert