g++ question

[zerofreeze]

i installed g++ compiler from synaptic manager but when i try to build a program it says "sh:g++: not found"

[Wybiral]

Use this command:



sudo apt-get install build-essential


To install everything you need. It's used with "g++", not "sh:g++" (I didn't know if that was intentional or now).

[zerofreeze]

Thanksfor help ;) ...please don't ignore me when i ask :)

[zerofreeze]

when i did u told me it said
mostafamagdy@ubuntu:~$ sudo apt-get install build-essential
Password:

when i enter my password it did nothing ...

[Wybiral]

Ignore you?

[Wybiral]

when i did u told me it said
mostafamagdy@ubuntu:~$ sudo apt-get install build-essential
Password:

when i enter my password it did nothing ...

You have to enter your password to use apt-get, then hit enter and it should begin installing the "build-essential" package (which contains all the header files and build requirements for using gcc/g++).

[zerofreeze]

yes because i really need help

[zerofreeze]

i did, i enetered the password and it said "Sorry, try again."

[Wybiral]

Maybe you mistyped the password? It is case sensitive.

[zerofreeze]

yes its working ...maybe the keyboard is old enough and want to be changed :)

[zerofreeze]

when i try another program en error said:
equation solver.cpp: error: '::main' must reutrn 'int' :
equation solver.cpp: In function 'int main()' :
equation solver.cpp: error: 'stricmp' was not declared in this scope
equation solver.cpp: error: 'getch' was not declared in this scope

what can i do ?

[Wybiral]

Can you post the code you're compiling?

[zerofreeze]

sorry for answering too late... Here's the code :
#include<iostream>

#include<cmath>

using std::cout;

using std::cin;

using std::endl;





class Root

{

public:

Root() {};

~Root() {};

void pres();

void select();

double root(double a, double b);

double root_part1(double a, double b, double c, double D);

double root_part2(double a, double b, double c, double D);

};



double Root::root(double a, double b)

{

return(-b/a);

}



double Root::root_part1(double a, double b, double c, double D)

{

return sqrt(D)/(2*a);#include<iostream>

#include<cmath>

using std::cout;

using std::cin;

using std::endl;





class Root

{

public:

Root() {};

~Root() {};

void pres();

void select();

double root(double a, double b);

double root_part1(double a, double b, double c, double D);

double root_part2(double a, double b, double c, double D);

};



double Root::root(double a, double b

}



double Root::root_part2(double a, double b, double c, double D)

{

return sqrt(-D)/(2*a);

}



void Root::pres()

{

cout << "================================================== ===========================\n";

cout << " Welcome to the equation solver! \n";

cout << " This program can solve any first or second degree polynomial equation \n";

cout << "================================================== ===========================\n\n";

}



void Root::select()

{

char car = (char)254;

char exp = (char)253;

cout << car << " For solving a first degree equation \"ax + b = 0\" enter '1' or enter '2' \n";

cout << car << " for solving a second degree equation \"ax" << exp << " + bx + c = 0\": ";

}



void main()

{

Root *p = new Root;

double a = 0, b = 0, c = 0;

int choix = 1;

double D = 0, A = 0, B = 0, C = 0;

char exp = ( char )253;

char answer[5] = "yes";

while( stricmp( answer, "no" ) != 0 )

{

p->pres();

p->select();

choix = getch();

cout << endl << endl;



switch(choix)

{

case '1':

cout << "a = ";

cin >> a;

cout << "b = ";

cin >> b;



while( a == 0 )

{

cout << "\"a\" can't be 0, please choose another value: ";

cin >> a;

}



cout << "your equation is: " << a << "x + " << b << " = 0" << endl;

cout << "the solution is: x = "<< p->root( a, b ) << "\n";

break;

case '2':

cout << "a = ";

cin >> a;



while( a == 0 )

{

cout << "\"a\" can't be 0, please choose another value: ";

cin >> a;

}



cout << "b = ";

cin >> b;

cout << "c = ";

cin >> c;



D = b * b - ( 4 * a * c );

A = -b/( 2 * a );

cout <<"\nthe equation is: " << a << "x" << exp << " + " << b << "x + " << c << " = 0 " << endl;

cout << "\nDelta = " << D << endl << endl;

if( D < 0 )

{

cout << "These equation have two complex roots" << endl;

cout << "the first one is: x1 = "<< A << " + " << p->root_part2( a, b, c, D ) << "i" << endl;

cout << "the second one is: x2 = "<< A << " - " << p->root_part2( a, b, c, D ) << "i" << endl;

}

else

{

cout << "These equation have two real roots" << endl;

cout << "the first one is: x1 = " << ( -b/( 2 * a ) ) + p->root_part1( a, b, c, D ) << "\n";

cout << "the second one is: x2 = " << ( -b/( 2 * a )) - p->root_part1( a, b, c, D ) << endl;

}

break;

default:

cout << "\n\nThis selection is unknown,select '1' or '2'\n";

}

cout << "\nDo you want to solve another equation ? ( Yes ) or ( No )" << endl;

cin >> answer;

while(( stricmp( answer, "yes" ) != 0 ) && ( stricmp( answer, "no" ) != 0 ))

{

cout << "Please only answer by \"yes\" or \"no\"!" << endl;

cin >> answer;

}

system("cls");

}

delete p;



}

[zerofreeze]

can u answer me plz ?

[LaRoza]

can u answer me plz ?

Can you use [ code ] or [ php ] tags, so we can all read the code?

[smartbei]

That, and remove uneccesary empty lines so we can read it in a single-digit number of pages? :D

Also, I actually wanted to see what was wrong but about the code you pasted...

Why is class Root defined twice?
What is:

double Root::root(double a, double b

} Supposed to be?
main should return an int - g++ won't compile otherwise.
You have your includes and your usings there twice.


Most of those are probably pasteing errors - fix those and we'll see about the rest :).