Polynomial program, Unknown Error.

This program compiles correctly but When i need to input data, it crashes saying "string subscript out of range", I dont know what it means. :(

I would really appreciate if someone can run the program and see if anything is missing.

I wrote this program with my class mate who knows more about this than I do. unfortunately I cant get in touch with him.

program is separated in 3 files. I really need to run some test with this thing. thank you.

Class

Code:

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#ifndef POLYNOMIAL_H
#define POLYNOMIAL_H

#include <iostream>
#include <string>
#include <cmath>
#include <iomanip>
using namespace std;

class Polynomial
{
        friend ostream &operator << ( ostream &, const Polynomial & );
        friend istream &operator >> ( istream &, Polynomial & );

public:
        Polynomial(); // default constructor
        Polynomial( int );
        Polynomial( string );
        Polynomial( const char * );
        Polynomial( const int *, int=0 ); // regular constructor
        Polynomial( const Polynomial & ); // copy constructor
        ~Polynomial(); // destructor

        void setPolynomial( int );
        void setPolynomial( string );
        void setDegree( int = 0, int = 0 );
        void setDegree( const char *, int = 0 );
        int getDegree( int = 0 );
        long long int eval( int = 0 );

        Polynomial operator+( const Polynomial & ) const;
        Polynomial operator+( const char * ) const;
        Polynomial operator+( int ) const;

        Polynomial operator-( const Polynomial & ) const;
        Polynomial operator-( const char * ) const;
        Polynomial operator-( int ) const;

        Polynomial operator*( const Polynomial & ) const;
        Polynomial operator*( const char * ) const;
        Polynomial operator*( int ) const;

private:
        int *ptr;
        int size;
};

#endif

---

Definition

Code:

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#include "Poly.h"

#include <iomanip>
#include <iostream>
#include <string>
#include <cmath>
using namespace std;


Polynomial::Polynomial()
{
        setPolynomial(0);
}

Polynomial::Polynomial( int input )
{
        setPolynomial( input );
}

Polynomial::Polynomial( string temp )
{
        setPolynomial( temp );
}

Polynomial::Polynomial( const char * temp )
{
        string tempstring = temp;
        setPolynomial( tempstring );
}

Polynomial::Polynomial( const int * coeff, int max )
{
        size = max;
        ptr = new int[size];
        for ( int i = 0; i < size; i++)
                setDegree(i, coeff[i]);
}

Polynomial::Polynomial( const Polynomial &polyToCopy )
{
        size = polyToCopy.size;
        ptr = new int[size];
        for ( int i = 0; i < size; i++)
                setDegree( i, polyToCopy.ptr[i] );
}

Polynomial::~Polynomial()
{
        delete [] ptr;
}

void Polynomial::setPolynomial(int input)
{
        size = 1;
        ptr = new int[size];
        ptr[0] = input;
}

void Polynomial::setPolynomial( string temp )
{
        string polyonly;
        char poly[100];
        int pos = 0, j = 0;

        for ( unsigned int i = 0; i <= temp.length(); i++)
        {
            if ( ( isdigit( temp[i] ) ) || ( temp[i] == '+' )
                || ( temp[i] == '-' ) || ( temp[i] == 'x' )
                || ( temp[i] == 'X' ) || ( temp[i] == '^' )
                || ( i == temp.length() ) )
                {
                        polyonly[j] = temp[i];
                        j++;
                }
        }

        for ( int i = 0; i <= j; i++ )
        {
                if ( (i == 0) || ( polyonly[i] == '+' ) || ( polyonly[i] == '-') )
                        pos = 0;
                if ( ( isdigit(polyonly[i] ) ) || ( polyonly[i] == '-' )
                || ( polyonly[i] == 'x' ) || ( polyonly[i] == 'X' )
                || ( polyonly[i] == '^') )
                {
                        poly[pos] = polyonly[i];
                        pos++;
                }

                if ((i == j) || ((i<j) && ((polyonly[i+1] == '-') || (polyonly[i+1] == '+'))))
                {
                        poly[pos] = '\0';
                        setDegree(poly,pos);
                }
        }
}

void Polynomial::setDegree( int degree, int coeff )
{
        if (degree >= size)
        {
                int oldsize = size;
                Polynomial temp(*this);
                size = degree+1;
                delete [] ptr;
                ptr = new int[size];

                for ( int i = 0; i < size; i++ )
                {
                        if ( i < oldsize )
                                ptr[i] = temp.ptr[i];
                        else if ( i >= oldsize )
                                ptr[i] = 0;
                }
        }

        if ( degree >= 0 )
                ptr[degree] = coeff;
}

void Polynomial::setDegree( const char *input, int max )
{
        int isNegative = 0;
        int foundX = 0;
        int coeff = 0;
        int degree = 0;
        int i;

        if ( input[0] == '-' )
                isNegative = 1;

        for ( i = 0; i < max; i++ )
        {
                if ( ( input[i] != '+' ) && ( input[i] != '-' ) )
                {
                        if ( ( input[i] == 'x' ) || ( input[i] == 'X' ) )
                        {
                                foundX = 1;
                                if ( coeff == 0 )
                                        coeff = 1;

                                if ( i == max - 1 )
                                        degree = 1;
                        }

                        if ( isdigit( input[i] ) )
                        {
                                if ( foundX == 0 )
                                {
                                        coeff *= 10;
                                        coeff += input[i] - '0';
                                }
                                else
                                {
                                        degree *= 10;
                                        degree += input[i] - '0';
                                }
                        }
                }
        }
        if ( isNegative == 1 )       
                coeff *= -1;       

        setDegree( degree,coeff );
}

int Polynomial::getDegree( int degree )
{
        if ( size > degree )
                return ptr[degree];
        else
                return 0;
}

long long int Polynomial::eval( int value )
{
        long long int total = 0;

        for ( int i = 0; i < size; i++ )
                total += ( long long int )ptr[i]*( ( long long int ) pow( ( float ) value,( float ) i ) );
                return total;
}

Polynomial Polynomial::operator+( const Polynomial &right ) const
{
        Polynomial temp;
        int max_size, value;
        max_size = ( size > right.size ) ? size : right.size;

        for ( int i = 0; i < max_size; i++ )
        {
                value = 0;

                if ( i < size )       
                        value += ptr[i];

                if ( i < right.size)
                        value += right.ptr[i];

                temp.setDegree(i,value);
        }
        return temp;
}

Polynomial Polynomial::operator+(const char *input) const
{
        string stringinput = input;
        Polynomial temp;
        temp.setPolynomial( stringinput );
        return *this + temp;
}

Polynomial Polynomial::operator+( int input ) const
{
        return *this + Polynomial( input );
}

Polynomial Polynomial::operator-( const Polynomial &right ) const
{
        Polynomial temp( right );
        for ( int i = 0; i < temp.size; i++ )
        temp.ptr[i] *= -1;
        return *this + temp;
}

Polynomial Polynomial::operator-( const char *input ) const
{
        string stringinput = input;
        Polynomial temp;
        temp.setPolynomial( stringinput );
        return *this - temp;
}

Polynomial Polynomial::operator-( int input ) const
{
        return *this - Polynomial( input );
}

Polynomial Polynomial::operator*( const Polynomial &right ) const
{
        Polynomial temp;
        int i, j;

        for ( i = 0; i < size; i++ )
        for ( j = 0; j < right.size; j++ )
                temp.setDegree(i+j,temp.getDegree(i+j)+ptr[i]*right.ptr[j]);

        return temp;
}
Polynomial Polynomial::operator*( const char *input ) const
{
        string stringinput = input;
        Polynomial temp;
        temp.setPolynomial( stringinput );
        return *this * temp;
}
Polynomial Polynomial::operator*( int input ) const
{
        return *this * Polynomial(input);
}

ostream &operator<<( ostream &output, const Polynomial &right )
{
        int didOut = 0;
        for ( int i = right.size - 1; i >= 0; i-- )
        {
                if ( right.ptr[i] != 0 )
                {
                        if ( right.ptr[i] > 0 )
                        {
                                if ( i != right.size - 1 )
                                        output << " + ";
                                else
                                {
                                        if ( i != right.size - 1)
                                                output << " - ";
                                        else       
                                                output << "-";
                                }
                                if ( ( fabs ((double)right.ptr[i])!= 1.0 ) || ( i == 0 ) )
                                {
                                        output << fabs((double)right.ptr[i] );
                                        didOut = 1;
                                }
                        }
                if ( i > 1 )
                        output << "x^" << i;
                else if ( i == 1 )
                        output << "x";
                }
        }

        if ( didOut == 0)
                output << 0;
        return output;
}

istream &operator>>(istream &input, Polynomial &right )
{
        string temp;
        getline( input, temp );
        right.setPolynomial( temp );
        return input;
}

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test program

Code:

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#include "Poly.h"

#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>
using namespace std;

int main()
{
        const int f_size = 4;
        int f_arr[f_size] = { 1, 1, 1, 1 };
        Polynomial f( f_arr,f_size );

        Polynomial g;
        cout << "Enter a polynomial (like:x^15+x^3-x-1) for 'g' (expecting x-1): ";
        cin >> g;

        Polynomial F;
        F.setDegree( 0, 1 );
        F.setDegree( 10, 1 );

        Polynomial G( F );
        G.setDegree( 10, -1 );
        G.setDegree( 15, 1 );

        cout << "Values of variables:" << endl;
        cout << "f = " << f << endl;
        cout << "g = " << g << endl;
        cout << "F = " << F << endl;
        cout << "G = " << G << endl;
        cout << endl;

        cout << "Evaluating f & F:" << endl;
        cout << " f( 0 ) = " << f.eval( 0 ) << endl;
        cout << " f( 1 ) = " << f.eval( 1 ) << endl;
        cout << "f( -2 ) = " << f.eval( -2 ) << endl;
        cout << " F( 0 ) = " << F.eval( 0 ) << endl;
        cout << " F( 1 ) = " << F.eval( 1 ) << endl;
        cout << "F( -2 ) = " << F.eval( -2 ) << endl;
        cout << endl;

        cout << "Testing overloaded operations:" << endl;
        cout << "      f + g: (" << f << ") + (" << g << ")" << endl;
        cout << "            = " << f + g << endl << endl;
        cout << "    f + 288: (" << f << ") + ( 288 ) " << endl;
        cout << "            = " << f + 288 << endl << endl;
        cout << "  f + ( 3x+1 ): ( " << f << " ) + ( 3x + 1 )" << endl;
        cout << "            = " << f + "3x + 1" << endl << endl;
        cout << "      f - g: (" << f << ") - (" << g << ")" << endl;
        cout << "            = " << f - g << endl << endl;
        cout << "      f * g: (" << f << ") * (" << g << ")" << endl;
        cout << "            = " << f * g << endl << endl;
        cout << "      F + G: (" << F << ") + (" << G << ")" << endl;
        cout << "            = " << F + G << endl << endl;
        cout << "      F - G: (" << F << ") - (" << G << ")" << endl;
        cout << "            = " << F - G << endl << endl;
        cout << "      F * G: (" << F << ") * (" << G << ")" << endl;
        cout << "            = " << F * G << endl << endl;
        cout << endl;

        cout << endl;
        system( "PAUSE" );
        return 0;
}

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Code:

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i <= temp.length();

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So don't walk off the end of your string if you don't want "you walked off the end of your string" error messages.

yea i dont get it...lol

I don't know how much clearer I can be. You are always and forever trying to process one more character than is present in your strings. Don't do that.

If the length of temp is N, then valid indexes are 0...N-1.
You are trying to iterate through 0...N.

I'll break it down.
You appear to understand how arrays are zero-based because you got these loops right:

Code:

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        for ( int i = 0; i < size; i++)
                for ( int i = 0; i < size; i++ )
        for ( i = 0; i < max; i++ )
        for ( int i = 0; i < max_size; i++ )
        for ( i = 0; i < size; i++ )
        for ( j = 0; j < right.size; j++ )

---

But you got this loop wrong, and were just as perplexed after the problem part was pointed out:

Code:

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        for ( unsigned int i = 0; i <= temp.length(); i++)

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One could easily conclude that you did not write the whole program yourself.
Do you or do you not understand how arrays are indexed?