c++ pointers to rows in dynamic matrix

Question

I have a dynamic matrix in a class created by allocating memory in this way:

int **m;   //this in the member head pointer


void allocate_mem(int ***ptr, unsigned r, unsigned c){
    *ptr = new int *[r];
    (*ptr)[0] = new int[r*c];
    for(unsigned i = 1; i < r; i++)
        (*ptr)[i] = (*ptr)[0] + i*c;
}

how can I call the pointers to the rows? I mean, m is the pointer to the array of pointers, *m is the pointer to the first row, but I don't know how to call the pointers to the other row

ooh three-star programmer ... anyway, try a std::vector for the storage. — Cheers and hth. - Alf
– Cheers and hth. - Alf, Commented Jan 26, 2014 at 17:04

Wojtek Surowka · Accepted Answer · 2014-01-26 16:52:02Z

3

*m is the pointer to the row with index 0 indeed, but *m is equivalent to m[0]. So for other indexes use m[index]

answered Jan 26, 2014 at 16:52

Wojtek Surowka

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