si un teatro tiene 12 asientos en la primera fila 16 en la segunda ,20 en la tercera asi sucesivamente hasta completar 20 filas
a) halla la cantidad de asientos que hay en la ultima fila
b) el total de asientos en el teatro
c) si te sientas en la fila 11 ¿cuantas personas se pueden sentar en la misma fila
Respuestas
truct group_info init_groups = {.usage = ATOMIC_INIT (2)};
struct group_info * groups_alloc (int gidsetsize) {
struct group_info * group_info;
int nblocks;
int i;
nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
/ * Asegúrese de que siempre asignemos al menos un puntero de bloque indirecto * /
nblocks = nblocks? : 1;
group_info = kmalloc (sizeof (* group_info) + nblocks * sizeof (gid_t *), GFP_USER);
if (! group_info)
devuelve NULL;
group_info-> ngroups = gidsetsize;
group_info-> nblocks = nblocks;
atomic_set (& group_info-> use, 1);
if (gidsetsize <= NGROUPS_SMALL)
group_info-> blocks [0] = group_info-> small_block;
else {
for (i = 0; i <nblocks; i ++) {
gid_t * b;
b = (void *) __ get_free_page (GFP_USER);
if (! b)
goto out_undo_partial_alloc;
group_info-> blocks [i] = b;
}
}
devolver group_info;
out_undo_partial_alloc:
while (--i> = 0) {
free_page ((sin signo largo) group_info-> blocks [i]);
}
kfree (group_info);
devuelve NULL;
}
EXPORT_SYMBOL (groups_alloc);
void groups_free (struct group_info * group_info)
{
if (group_info-> blocks [0]! = group_info-> small_block) {
int i;
para (i = 0; i <group_info-> nblocks; i ++)
free_page ((sin signo largo) group_info-> bloques [i]);
}
kfree (group_info);
}
EXPORT_SYMBOL (groups_free);
/ * exportar group_info a una matriz de espacio de usuario * /
static int groups_to_user (gid_t __user * grouplist,
const struct group_info * group_info)
{
int i;
unsigned int count = group_info-> ngroups;
for (i = 0; i <group_info-> nblocks; i ++) {
unsigned int cp_count = min (NGROUPS_PER_BLOCK, cuenta);
unsigned int len = cp_count * sizeof (* grouplist);
if (copy_to_user (grouplist, group_info-> blocks [i], len))
return -EFAULT;
grouplist + = NGROUPS_PER_BLOCK;
count - = cp_count;
}
devuelve 0;
}
/ * rellene un group_info desde una matriz de espacio de usuario: ya debe estar asignado * /
static int groups_from_user (struct group_info * group_info,
gid_t __user * grouplist)
{
int i;
unsigned int count = group_info-> ngroups;
for (i = 0; i <group_info-> nblocks; i ++) {
unsigned int cp_count = min (NGROUPS_PER_BLOCK, cuenta);
unsigned int len = cp_count * sizeof (* grouplist