Compilare: user.c: In function ‘main’: user.c:17:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] int *sieve = (int*)malloc((B + 1) * sizeof(int)); ^ user.c:17:24: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] int *sieve = (int*)malloc((B + 1) * sizeof(int)); ^ user.c:47:12: warning: ‘bj’ may be used uninitialized in this function [-Wmaybe-uninitialized] fprintf(fout, "%d %d\n", bi, bj); ^ user.c:47:12: warning: ‘bi’ may be used uninitialized in this function [-Wmaybe-uninitialized]