pointer to matrix

I have two different twodimensional matrixes of the same size

Code:

---

Square Matrix1[MTR_WIDTH][MTR_HEIGHT];
Square Matrix2[MTR_WIDTH][MTR_HEIGHT];

---

Now I am only using one of them at a time, the other serves as a storage matrix in the mean time. So I wan't to have a pointer pointing to the one currently in use. I have tried this:

Code:

---

Square *CurrentMatrix[MTR_WIDTH][MTR_HEIGHT] = Matrix1;

---

But it doesn't work, "conflicting declaration 'Square*CurrentMatrix[160][120]' ".

I have tried some different ways but can't figure out how to write it. Can someone help me please?

Something like this is possible.

Code:

---

#include <iostream>

const int W = 2;
const int H = 2;

void print(int* array)
{
    for (int i = 0; i < W; i++) {
        for (int j = 0; j < H; j++) {
            std::cout << *array++ << " ";
        }
    std::cout << std::endl;
    }
}

int main()
{
    int a[W][H] = {{33, 34}, {35, 36}};
    int b[W][H] = {{100, 110}, {120, 130}};
    int* c;
    c = &a[0][0];
    print(c);
    c = &b[0][0];
    print(c);
    std::cin.get();
}

---

In your case you would need a Square pointer initialized to the first element in the 2D array. It is your responsibility to know, how many Squares you may access with this pointer (MTR_WIDTH*MTR_HEIGHT) using pointer arithmetics.

(By the way, you can pass 2D arrays to functions as well if you changed the signature. Then you wouldn't need c at all.)

You can also use pointer to array

Code:

---


#include <iostream>

const int W = 2;

void print(int(* array)[W],int height)
{
    for (int i = 0; i < W; i++)
    {
        for (int j = 0; j < height; j++)
        {
            std::cout << array[i][j] << " ";
        }
        std::cout << std::endl;
    }
}

int main()
{
    const int H = 2;
    int a[W][H] = {{33, 34}, {35, 36}};
    int b[W][H] = {{100, 110}, {120, 130}};
    int(* c)[W];
    c = a;
    print(c,H);
    c = b;
    print(c,H);
    std::cin.get();
    return 0;
}

---

Maybe only Square** pointer_to_current_2d_array; will do the trick :)
you could evaluate it like this: pointer_to_current_2d_array = &Matrix1;

Imho it should work.

Quote:

---

Originally Posted by hardi

Maybe only Square** pointer_to_current_2d_array; will do the trick :)
you could evaluate it like this: pointer_to_current_2d_array = &Matrix1;

Imho it should work.

---

I think you should try to compile it before suggesting

Quote:

---

Originally Posted by vart

I think you should try to compile it before suggesting

---

yep, It didn't work. sorry

Thanks vart! It worked perfectly fine. I solved it like this:

Code:

---

Square Matrix1[MTR_WIDTH][MTR_HEIGHT];
Square Matrix2[MTR_WIDTH][MTR_HEIGHT];
Square (*CurrentMatrix)[MTR_HEIGHT] = Matrix1;

---

Also anon's way worked, but it was a little bit more complicated in that case.