How about 3D array (Matrix vs Malloc)

//after last post I just asked myself "how about a 3D array, I have never done something like this"
//Challenge accepted
//And I'm surprised now

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

//for variable m, you need to know the number os columns and height!
void testOne(int m[][2][5], int r, int c, int h) {
    int x, y, z, a = 0;
    for (x = 0; x < r; x++) {
        for (y = 0; y < c; y++) {
            for (z = 0; z < h; z++) {
                m[x][y][z] = ++a;
            }
        }
    }
}

int* testTwo(int r, int c, int h) {
    int* m;
    int x, y, z, a = 0;
    m = malloc(sizeof(int) * c * r * h);
    if (m == NULL) {
        printf("Error allocating memory!");
        exit(1);
    }
    //that's funny, I never though it's like this :o
    //I needed a paper to make some maths
    for (x = 0; x < r*(h + c); x += (h + c)) {
        for (y = 0; y < c * h; y += h) {
            for (z = 0; z < h; z++) {
                m[x + y + z] = ++a;
            }
        }
    }
    /*
    alternative
    for (z = 0; z < h; z++) {
        for (y = 0; y < c; y++) {
            for (x = 0; x < r; x++) {
                m[z * (r*r) + y * c + x] = ++a;
            }
        }
    }
    */
    return m;
}

int main() {
    int a[2][2][5], x, y, z, rows = 2, cols = 2, height = 5;
    int* b = NULL;

    testOne(a, rows, cols, height);
    for (x = 0; x < rows; x++) {
        for (y = 0; y < cols; y++) {
            for (z = 0; z < height; z++) {
                printf("%d ", a[x][y][z]);
            }
            printf("\n");
        }
    }
    printf("\n\n\n");
    b = testTwo(rows, cols, height);
    for (x = 0; x < rows*(height + cols); x += (height + cols)) {
        for (y = 0; y < cols * height; y += height) {
            for (z = 0; z < height; z++) {
                printf("%d ", b[x + y + z]);
            }
            printf("\n");
        }
    }
    free(b);

    return 1;
}