Hello everyone,

My project consists of reading 2 lines of integers separated by white spaces corresponding coefficents and exponents,

each line representing a polynominal.

I have to add both polynominals and subtract them.

I have made a linked list class to hold each coefficent and exponent in a node.

The problem I have is making multiple copies of the original polynominal.

I have a the polynominal sorted in Linkedlist current and I made another Linkedlist call add

when I add the polynomials in LinkedList add, it does the same to my current LinkedList.

I want to know how can I make separate copies so each is dependent?

I know it passes the same pointer to each Linkedlist but is there a way not to?

```
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
using namespace std;
class Node{
public:
int coef;
int exp;
Node* next;
Node(){
coef = 0;
exp = 0;
next = NULL;
}//default constructor
Node(int c, int e){
if(e < 0){
cout << "Exponent is negative" << endl;
exit(1);
}//if check if exponent is < 0
coef = c;
exp = e;
next = NULL;
}//2 param constructor
~Node(){
delete next;
}//destructor
};
class LinkedList{
public:
Node* start;
LinkedList(){
start = NULL;
}//default constructor
LinkedList(const LinkedList& l){
Node* temp = l.start;
if(temp == NULL){
cout << "List is empty";
exit(1);
}//if
else{
while(temp != NULL){
this->add(temp);
temp = temp->next;
}//while
}//else
}//copy constructor
~LinkedList(){
delete start;
}//destructor
void add(Node*& n){
if(start == NULL){
start = n;
start->next = NULL;
}//if
else{
Node* temp = start;
if(n->exp >= temp->exp){
n->next = temp;
start = n;
return;
}//if
else{
while(temp!= NULL){
if(n->exp >= temp->next->exp){
n->next = temp->next;
temp->next = n;
return;
}//if
temp = temp->next;
}//while
}//else
}//else
}//add
void display(){
Node* temp = start;
do{
if(temp == NULL){
cout << "List is empty" << endl;
return;
}//if
else{
cout << temp->coef << " ";
cout << temp->exp << " ";
}//else
temp = temp->next;
}//do
while(temp != NULL);//while
cout << endl;
}//display
void operationAdd(){
Node* temp = start;
//if empty list or only 1 node
if(temp == NULL || temp->next == NULL)
return;
while(temp != NULL){
if(temp->next == NULL)
break;
if(temp->exp == temp->next->exp){
temp->coef += temp->next->coef;//add the coef
Node* temp1 = temp->next;//temp1 holding it
temp->next = temp1->next;//set temp next = to temp->next->next
}//if
else{
if(temp->next == NULL)
break;
temp = temp->next;//if not keep going
}//else
}//while
}//operationAdd
};
int main()
{
LinkedList* current = new LinkedList;
string line;
int repeat = 0;
ifstream myfile("input.txt");
if(myfile.is_open()){
while(!myfile.eof()){
getline(myfile, line);
repeat++;
cout << "\nLine: " << repeat << " \n";
cout << line << endl;
int num=0, c=0, e=0;
stringstream str(line);
while(str >> num){
c = num;
str >> num;
e = num;
Node* temp = new Node(c,e);
current->add(temp);
}//while
}//while
myfile.close();
}//if
else cout << "Unable to open file" << endl;
cout << "\nSorted List: " << endl;
current->display();
cout << endl;
LinkedList* add = new LinkedList;
add = current;//how can I make add be a separate copy of current?
add->operationAdd();
add->display();
current->display();
return 0;
}
```

my output

Line: 1

-1 0 5 1 20 3 -9 2 -2 1 1 2 -2 3 1 9 6 3 2 2 -1 1 10 0

Line: 2

5 2 -2 9 10 3 4 0 -3 1 1 1 6 3 -4 3 -5 2 8 8 9 4 4 4

Sorted List:

-2 9 1 9 8 8 4 4 9 4 -4 3 6 3 10 3 6 3 -2 3 20 3 -5 2 5 2 2 2 1 2 -9 2 1 1 -3 1 -1 1 -2 1 5 1 4 0 10 0 -1 0

-1 9 8 8 13 4 36 3 -6 2 0 1 13 0 --add->display

-1 9 8 8 13 4 36 3 -6 2 0 1 13 0 -- current->display

I only called operationAdd on the "add" linkedlist but it does the same to my current linkedlist.

I want current to stay

-2 9 1 9 8 8 4 4 9 4 -4 3 6 3 10 3 6 3 -2 3 20 3 -5 2 5 2 2 2 1 2 -9 2 1 1 -3 1 -1 1 -2 1 5 1 4 0 10 0 -1 0

so I can use that to subtract but whatever I do to "add" linkedlist it does the same to "current".

Please help.