Compilare: user.cpp: In function ‘int main()’: user.cpp:13:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=s.size();i++) ^ user.cpp:22:35: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(k%2!=(int)c-48) {ok='N';ok1='U';l++;v[l]=i/8;} ^