2D vector

[islam.fci.3]

I want to write a class that do operation on two matrices by 2D vector but i have some problems with the 2D vector , any one can help me?

[yxBen]

and what are those problems?

[Lucaci Andrew]

It's kinda hard for us to figure out your problems since you didn't share them with us.

[islam.fci.3]

I want to let the user to input elements of the vector....
then i want to multiply two 2D vectors
i wrote a code but there is logic errors

[islam.fci.3]

PLZ.. write the code of entering two 2D vectors and multiply them ,then show results,
using class that take elements of the vector ,multiply and show result

[tinstaafl]

Show the code and outline the errors. Unless you're willing to pay someone to do the work for you, in which case you should be in Jobs and Resumes forum.

[islam.fci.3]

it's the code , debug it and tell me what is the error

#include <iostream>
using namespace std;
#include <vector>
class matrix
{
protected:
    int r,c;                    //r is rows c is columns
    char op;                    // op is the operarion
    vector<vector<double> > elements;           //vector for matrix elements
public:
    matrix()                                    //constructor for initializing r,c,op and vector to 0
    {
         r='c';c='a'; op='b';
  for ( int i = 0; i < 5; i++ ) {
   elements.push_back ( vector<double>() );
    for ( int j = 0; j < 5; j++ )
        { 
    elements[i].push_back ( 0 );}
  }
    }
////////////////////////////////////////////////////////////

    void get_data()                          //get elements of the matrix from the user
    {
        char a;
        double n;
        cout<<"\n\nEnter type of the matrix in form r*c\n\n";
        cin>>r>>a>>c;
        cout<<"Enter the element of the matrix\n\n";
              for ( int i = 0; i < r; i++ ) {
   elements.push_back ( vector<double>() );
    for ( int j = 0; j < c; j++ )
    {

        cin>>n;
        elements[i].push_back (n );}
  }
    }
////////////////////////////////////////////////////////////

    void operation(matrix mat1,matrix mat2)                 //do operations on two matrices
    {

        cout<<"Enter the operation you want (+,-,*)\n\n";
        cin>>op;
        switch(op)                                           //if the operation +,-,*
        {
        case '+':
            if(mat1.r==mat2.r&&mat1.c==mat2.c)              //if the matrices have the same type it can sum
            {
                for(int i=0;i<mat1.r;i++){
                    for(int j=0;j<mat1.c;j++){
                        elements[i][j]=mat1.elements[i][j]+mat2.elements[i][j];}
                }
            }
            else
                cout<<"\nERROR You Enterd Tow Matrices Of Different Type\n\n";
            break;

            ////////////////////////////////////////////////////////////

        case'-':
            if(mat1.r==mat2.r&&mat1.c==mat2.c)         //if the matrices have the same type it can subtract
            {
                for(int i=0;i<mat1.r;i++){
                    for(int j=0;j<mat1.c;j++){
                        elements[i][j]=mat1.elements[i][j]-mat2.elements[i][j];}
                }
            }
            else
                cout<<"\nERROR You Enterd Tow Matrices Of Different Type\n\n";
            break;

            ////////////////////////////////////////////////////////////

        case'*':
            if(mat1.c==mat2.r)    //if number of first matrix columns equal number of second matrix rows
            {
                for ( int i = 0; i < mat1.r; i++ )           //initialize the vector of the result to 0
                {                  
                 elements.push_back ( vector<double>() );
                  for ( int j = 0; j < mat2.c; j++ ){

                      elements[i].push_back (0 );}}
                ////////////////////////////////////////////////////////////

                for(int i=0;i<mat1.r;i++)                //multiplying
                {
                    for(int j=0;j<mat2.c;j++)
                    {
                        for(int k=0;k<mat1.c;k++)
                            elements[i][j]=elements[i][j]+mat1.elements[i][k]+mat2.elements[k][j];
                    }
                }
  }
                             else
                    { cout<<"\n Input matrices can not be multiplied\n";
                 cout<<" The number of columns in first matrix must equal number of rows of the second matrix\n";}
            break;
        default:
            cout<<"\nYou Entered Error sign\n\n";
    }
            }
////////////////////////////////////////////////////////////

    void sow_data(matrix mat1,matrix mat2)               //show the result
    {
        if(op=='+'||'-')                                //if the operation is + or -
        {
            for(int i=0;i<mat1.r;i++){
                for(int j=0;j<mat1.c;j++)
                    cout<<elements[i][j]<<'   ';
                cout<<"\n\n";
            }
        }
        else if(op=='*')                                //if the operation is multiplying
        {
            for(int i=0;i<mat1.r;i++){
                for(int j=0;j<mat2.c;j++)
                    cout<<elements[i][j]<<'   ';
                cout<<"\n\n";
            }
        }
        else
            cout<<"\nERROR\n";
    }


};
int main()
{
    matrix mat,mat1,mat2;
    mat1.get_data();
    mat2.get_data();
    mat.operation(mat1,mat2);
    mat.sow_data(mat1,mat2);
    return 0;
}

[tinstaafl]

outline the errors.

Lots of comments but nothing about what it's doing wrong