Question

I am going to multiply two polynomial that user must enter.

in the first step (getting info from user) I got this error:

Unhandled exception at 0x00a315cb in linked polinomials.exe:
  0xC0000005: Access violation writing location 0x00000000.

I got this error after that I want to enter an other element of polynomial.

struct polynomial{

    float coef ;
    int exp ;
    polynomial *next ;
} *first, *second ,*result;

first = new(polynomial);
   //init first
first ->coef = 0;
first->exp = 0 ;
first->next = 0;

while(ch != 'n')
{
    cin >> temp_c ;
    cin >> temp_e ;
    first->coef = temp_c;
    first->exp = temp_e;
    cout << "Do you want to enter another ? (y or n) :" << endl;
    ch = getch();
    first = first->next;
}

Answer 1

In the first iteration:

first = first->next;

you assign first to NULL, because that’s what first->next is initially. You need to allocate space for it before the assignment.

first->next = new polynomial;
first = first->next;

Also, are you sure you want to lose the pointer to the first node?