Dynamic memory allocation for two-dimensional arrays

When the memory is requested, the rows are allocated first, and then the columns are allocated;

void Malloc2darray (int **parr, int x, int y) {    int i;    PARR = (int * *) malloc (x * sizeof (int *));    if (!parr)    {        printf ("Dynamic request memory failed!") \ n ");        return NULL;    }        for (i = 0; i < x; i + +)    {        parr[i] = (int *) malloc (y * sizeof (int));        if (!parr[i])        {            printf ("Dynamic request memory failed!") \ n ");            return NULL;}}    }

When the memory is freed, the column is released first, and then the row is released;

void Free2darray (int **parr, int x, int y) {    int i;    for (i = 0; i < x; i + +)    {free        (parr[i]);        Parr[i] = NULL;    }    Free (PARR);    

However, the problem with this is that allocating memory is not contiguous and there is a problem with the whole block of memory operations.

The following code allocates memory that is contiguous

void Malloc2darray2 (int **parr, int x, int y) {    int i;    PARR = (int * *) malloc (x * sizeof (int *));    if (!parr)    {        printf ("Dynamic request memory failed!") \ n ");        return NULL;    }        PARR[0] = (int *) malloc (x * y * sizeof (int));    if (!parr[0])    {        printf ("Dynamic request memory failed!") \ n ");        Free (PARR);        return NULL;    }        for (i = 0; i < x; i + +)        parr[i] = parr[i-1] + y;//index associated with the corresponding data address        memset (p[0], 0, nheight * nwidth);//two-dimensional array clear 0}v OID free2darray2 (int **parr, int x, int y) {free    (parr[0]);    Parr[0] = NULL;        Free (PARR);    

Reference Http://03071344.lofter.com/post/10871e_34cade

Dynamic memory allocation for two-dimensional arrays