/*
 * matrixpointer.c
 *
 * Beispiel-Programm Matrix als Feld von Feldern.
 * Siehe zum Vergleich matrixpointerpointer.c
 *
 * Autor: H.Drachenfels
 * Erstellt am: 29.10.2022
 */

#include <stdio.h>
#include <stdlib.h>

#define M 3 // number of columns

int main(void)
{
    //--------------------- allocate and initialize memory for 2x3-matrix
    const int n = 2; // number of lines
    int (*matrix)[M] = (int(*)[M]) malloc(n * sizeof (int[M]));
    if (matrix == NULL)
    {
        printf("Speicherallokierungsfehler\n");
        return 1;
    }

    matrix[0][0] = 10;
    matrix[0][1] = 11;
    matrix[0][2] = 12;
    matrix[1][0] = 20;
    matrix[1][1] = 21;
    matrix[1][2] = 22;

    //--------------------------------- print matrix addresses and values
    printf("&matrix = %p\n", (void*) &matrix);
    printf("matrix = %p\n", (void*) matrix);

    for (int i = 0; i < n; ++i)
    {
        printf("[%d] %p: %p\n", i, (void*) &matrix[i], (void*) matrix[i]);

        for (int j = 0; j < M; ++j)
        {
            printf("  [%d] %p: %d\n", j, (void*) &matrix[i][j], matrix[i][j]);
        }
    }

    //------------------------------------------------- print matrix size
    printf("sizeof matrix = %zu\n", sizeof matrix);
    printf("%d * sizeof *matrix = %zu\n", n, n * sizeof *matrix);

    free(matrix);
    return 0;
}