Compilare: user.cpp: In function ‘int main()’: user.cpp:151:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i == P.size() - 1) sg = -1; ^ user.cpp:48:8: warning: unused variable ‘A’ [-Wunused-variable] int N,A,B,C,i,sg,vf,flag; ^ user.cpp:48:10: warning: unused variable ‘B’ [-Wunused-variable] int N,A,B,C,i,sg,vf,flag; ^ user.cpp:48:12: warning: unused variable ‘C’ [-Wunused-variable] int N,A,B,C,i,sg,vf,flag; ^