creating multiple matrix with different constructors - c++

Question

I have an assignment where i need to use a matrix class of type T elements. I have a constructor using 2 int, one copy constructor, one constructor using a string and a destructor. matrix A uses first constructor and works fine, matrix B uses second and also prints out fine but i have an issue with matrix C. If I a declare it by itself(removing matrix a and b from main) it prints as well, but when all is there, it prints out something like:
3735748 3745176
3745176 3735748
(instead of
5 6
7 8)
And numbers change everytime I compile.
I feel like this should be obvious but i'm a beginner and cant figure it out.. Any help welcome! Thank you
template <class T>
class matrice
{
private :
unsigned int nLignes; //number of rows
unsigned int nColonnes; //nbr of cols
T** rep;
public :
matrice( unsigned int nl, unsigned int nc)
{
setLignes(nl);
setColonnes(nc);
rep = new T*[nl];
for(int i = 0; i < nl; i++){
rep[i] = new T[nc];
}
for(int i = 0; i < nl; i++){
for(int j = 0; j < nc; j++){
rep[i][j] = (T) i*j;
}
}
}
matrice( const matrice& mat)// my copy constructor
{
setLignes(mat.nLignes);
setColonnes(mat.nColonnes);
rep = new T*[nLignes];
for(int i = 0; i < nLignes; i++){
rep[i] = new T[nColonnes];
}
for(int i = 0; i < nLignes; i++){
for(int j = 0; j < nColonnes; j++){
rep[i][j] = (T) i*j;
}
}
}
matrice( const std::string& UnString)//constructor using a string
//"nl,nc,val1, val2.."
{
std::vector<int> vect;
std::stringstream ss(UnString);
int i;
while (ss >> i)
{
vect.push_back(i);
if (ss.peek() == ',')
ss.ignore();
}
setLignes(vect.at(0));
setColonnes(vect.at(1));
int taille = nLignes * nColonnes;
vect.erase(vect.begin(), vect.begin()+2);
if(taille == vect.size()){ // making sure enough values to
//fill array
int n = 0;
for(int i = 0; i < nLignes; i++){
rep[i] = new T[nColonnes];
}
for(int i = 0; i < nLignes; i++){
for(int j = 0; j < nColonnes; j++){
rep[i][j] = vect.at(n);
n++;
}
}
}
}
~matrice()
{
delete[] rep;
}
void afficher();//printing function
void setLignes(int l)
{
nLignes = l;
}
void setColonnes(int c)
{
nColonnes = c;
}
};
template <class T>
void matrice<T>::afficher()//printing function
{
int i,j;
for (i=0;i < nLignes;i++)
{
for(j=0;j < nColonnes;j++)
{
cout << rep[i][j] << " ";
}
cout << "\n";
}
}
/*
*
*MAIN*
******/
int main(int argc, char *argv[])
{
matrice <unsigned int> mat(5,3);//MATRIX A
matrice <unsigned int> a = mat;
a.afficher();
{
matrice <unsigned int> mat(6,6);//MATRIX B
matrice <unsigned int> b = mat;
b.afficher();
}
matrice <unsigned int> c("2,2,5,6,7,8");//MATRIX C !! problem
c.afficher();
system("pause");
return 0;
}

Answer 1

You forget allocate space for rep in the constructor using a string.
Moreover, your deconstructor is at risk of memory leaking, please check it yourself.