macierze

#include <iostream>
#include <vector>

using namespace std;

struct matrix{
    int rows;
    int cols;
    vector<vector<float> > data;

    matrix();
    matrix(int nrows, int ncols,vector<vector<float> > ndata);
    void display();
};

matrix * operator *(matrix &jedna, matrix &druga);
bool mult_condition(matrix &jedna, matrix &druga);

matrix::matrix(){
    rows=0;
    cols=0;
}

matrix::matrix(int nrows, int ncols, vector<vector<float> > ndata)
{
    rows = nrows;
    cols = ncols;
    data = ndata;
    data.resize(rows,vector<float>(cols));
}

void matrix::display(){

    int k=0;
    for(vector<vector<float> >::iterator i= data.begin(); i != data.end(); ++i, ++k){
        int l=0;
        for(std::vector<float>::iterator j= data.at(k).begin(); j != data.at(k).end(); ++j, ++l){
            cout << data.at(k).at(l) << " ";
        }
        cout << endl;
    }

    cout << endl;
}

bool mult_condition(matrix &jedna, matrix &druga){
    return (jedna.cols==druga.rows);
}

matrix * operator *(matrix &jedna, matrix &druga){
    if (!mult_condition(jedna, druga)) return NULL;

    vector<vector<float> >  result(jedna.rows, vector<float>(druga.cols ,1));
    float tmp;

    for(int i=0; i<jedna.rows; i++){
        for (int j=0; j<druga.cols; j++){
        tmp = 0;
            for(int k=0; k<jedna.cols; k++){
                tmp += jedna.data[i][k]*druga.data[k][j];
            }
            result[i][j] = tmp;
        }
    }


    matrix * wynik = new matrix(jedna.rows, druga.cols, result);
    wynik->display();
    return wynik;
}


int main()
{
    matrix a(3, 2, {{1, 2}, {1, 1}, {0, 2}});
    matrix I(2, 2, {{1, 0}, {0, 1}});

    a.display();
    I.display();

    matrix * b = a*I;

    delete b;

}