Compilare: user.cpp: In function ‘int main()’: user.cpp:75:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos<=D.size()/2) ^ user.cpp:84:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=pos+1;i<=D.size();++i) ^ user.cpp:101:13: warning: unused variable ‘x’ [-Wunused-variable] int x=*it; ^