Kalhspera! Ti exete na shmeiwsete ?

Code:

void foo(int **mat, int rows, int cols) {     int i, j;     for (i = 0; i < rows; i++) {         for (j = 0; j < cols; j++)             printf("%d ", mat[i][j]);         printf("\n");     } } int mat[3][3] = { {1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; foo((int **)&mat[0][0], 3, 3);

Filika,
Sta9hs

O pinakas mat einai sto stack kai den einai pinakas pou periexei diktes opos to thelei h foo
giauto ektyponei otinanai - auto ypothetw gt dn exw xrono gia na to trexw :PP.

Enw yparxei eidiko section me challenges den katalavainw giati analonomaste se quizakia pou malista polu mikri sxesh exoun me ta real world programming problems...

H prosopiki mou gnwmh einai oti xrhsimopoihte la8os to section ayto... so far.



Filika

Thiseas

Loipon katarxhn tha parakalousa o, ti themata einai sxetika me protaseis diaxeirishs kai organwshs tou forum mporoun na ginontai eite sto Section "Protaseis" , eite sto irc sto #codemasters, opou ola ta paidia einai ekei synexeia kai kata th diarkeia ths hmeras sigoura tha epikoinwnhsoume oloi me olous.

Tha kleisw auth thn parenthesh sto quiz auto legontas th dikia mou skepsh gia to forum( mias kai hmoun egw kuriws pou entharruna ton Beket na vazei askhseis-quiz sto section auto).

Katarxhn sta programming challenges mpainoun askhseis pou xreiazontai thn plhrh anaptuxh tou programmatos.
Twra, se kathe subthread mporoun na mpoun OLA ta upoloipa, o,ti kai an einai auta: apories, askhseis, vohthhtikes synarthseis, quiz, parathrhseis, bugs, oloklhra projects. Mexri stigmhs exoun mpei mono quiz...ok.. opoios thelei einai eleftheros na vazei o,ti thelei arkei na einai sto swsto section.
Kai mia gnwmh gia ta quiz: ena mikro quiz, opws kai ta hdh uparxonta kai sxoliasmena, mporoun na lusoun 1-2-3 apories, oi opoies nai men fainontai mikres alla einai kairies. Epishs se kathe quiz zhteitai kai mia improvement tou kwdika( gia paradeigma to scanf("%d",integer).. se ena megalo project an den einai kai toso sovaro kai den mas endiaferei h asfaleia tou kai h plhrhs akeraiothta tou tote den nomizw oti tha katsei kaneis na grapsei parapanw grammes kwdika gia na ta diasfalisei ayta.) Mesw enos quiz omws kaneis den tha varethei na grapsei 10 grammes kwdika, oi opoieis tha einai kai o apolutos swstos kwdikas kai etsi mathainoume na programmatizoume swsta..( h toulaxisotn na xeroume na to kanoume.. kai opoios thelei to pragmatopoiei sta dika tou sources)


ps: Ayta gia o,ti sxetiko me ta erwthmata pou tethhkan. Tha parakalousa otidhpote allo na metaferthei sto "protaseis" kai apo edw kai pera na sunexisoume to commenting tou quiz autou.( Den hthela na grapsw tosa, to ekana omws giati mou exefrasan kai alloi tis amfivolies tous gia to nohma twn "quiz")

TO provlima einai to mat[i][j] stin foo().
Ipotheto pos o compiler den mporei na katalavei ti posa stoixeia na paei na diavasei apo to &mat[0][0] afou den mporei na ipologisei to *(math + i*X + j); ara to vazoume emeis
stin printf("%d", *(math + i * cols + j));
sosta?

Bekete enoeis
auto *(mat + i * columns + j);
?

H swsth ekfrash Monra einai:

Code:

*((int *)mat + cols * i) + j)

Synopsizontas, exoyme tis ekshs dyo lyseis:

1h lysh -- pointer arithmetics:

Code:

void foo1(int **mat, int rows, int cols) {     int i, j;     for (i = 0; i < rows; i++) {         for (j = 0; j < cols; j++)             printf("%d ", *((int *)mat + cols * i) + j);         printf("\n");     } }

2h lysh -- endiamesoi voh9htikoi pointers:

Code:

void foo2(int **mat, int rows, int cols) {     int i, j;     int **aux;     aux = malloc(rows * sizeof(int *));     if (aux == NULL) {         perror("malloc");         exit(EXIT_FAILURE);     }     for (i = 0; i < rows; i++) {         aux[i] = (int *)mat + cols * i;         for (j = 0; j < cols; j++)             printf("%d ", aux[i][j]);         printf("\n");     }     free(aux); }

Filika,
Sta9hs