Discussion in 'C++' started by imported_nahid, Nov 21, 2010.

1. ### imported_nahidNew Member

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Hi ,
I'm new in C++ programming and I need help.
I wanna write a class named polynomial that can be used like this :

Code:
```int main()
{
vector<double> ac;
ac.push_back(10);
ac.push_back(3);
const Poly a(ac); // a contains 3x + 10

vector<double> bc;
bc.push_back(1);
bc.push_back(0);
bc.push_back(4);
const Poly b(bc); // b contains 4x^2 + 1

Poly c = a + b; // c contains 4x^2 + 3x + 11
c += b; // c contains 8x^2 + 3x + 12

Poly d = c * 2; // d contains 16x^2 + 6x + 24
cout << d << endl; // prints 16x^2+6x+24 in the output

d = -1 * b; // d contains -4x^2 - 1
cout << d << endl; // prints -4x^2-1 in the output

cout << d(2) << endl; // evaluates d with x=2, the result is -17       // same as caling d.operator()(2)

cout << d[0] << endl; // prints -1 which is the coefficient of x^0
cout << d[1] << endl; // prints 0 which is the coefficient of x^1
cout << d[2] << endl; // prints -4 which is the coefficient of x^2
cout << d[3] << endl; // prints 0 which is the coefficient of x^3

d[1] = 7; // d now contains -4x^2 + 7x -1
d[4] = 1; // d now contains x^4 - 4x^2 + 7x -1
cout << b[2] << endl; // prints 4

return 0;
}

and I don't understand how to write inside the member functions.

//poly.h

class Poly
{
public:
Poly( vector<double> a ):p(a){}

Poly& operator+= ( const Poly& c );              //this+=c
Poly operator* ();
Poly operator+ ( Poly& a ) const;
double operator()( const double b ) const;
double operator[]( const double d ) const;

friend Poly operator<< ( ostream& out , Poly& q );
private:
vector<double> p ;
};
```
I think my class should be something like this

thanks

2. ### imported_nahidNew Member

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I some how completed my class and I need help to make it the best

plz help me.

" code has been attached "

3. ### go4expertModerator

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What do you mean by best?

4. ### imported_nahidNew Member

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It isn't important
It's just my slogan
I just wanna make my program run
just help me

thanks;

5. ### go4expertModerator

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So consider that is the best method.

6. ### techgeek.inNew Member

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7. ### go4expertModerator

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8. ### techgeek.inNew Member

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Great!! now u know this...

9. ### imported_nahidNew Member

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excuse me!
are you having fun here or really really wanting to help persons like me solve their problems :-?

10. ### NewsBotNew Member

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This is one of the main reason for this

11. ### imported_nahidNew Member

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I don't understand!!!!!!
every one here just had answered the questions for competition and now they won't answer?????(after this )

12. ### go4expertModerator

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That is not true from my end because I am member of this forum for quite sometime and yes some people used the competition in the wrong way and I think I had to reply back and cannot sit back see someone bashing on me.

Anyways your program is quite good.

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