Compilare: user.cpp: In function ‘int mask(int, int)’: user.cpp:13:54: warning: operation on ‘step’ may be undefined [-Wsequence-point] return int( (arg & ((BYTE-1LL)<<--step*8))>>step*8 ); ^ user.cpp: In function ‘int main()’: user.cpp:55:28: warning: format ‘%lld’ expects argument of type ‘long long int’, but argument 3 has type ‘int’ [-Wformat=] fprintf(fo,"%lld ",v[i]); ^ user.cpp:46:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d %d %d",&n,&a,&b,&c); ^