Compilare: user.cpp: In function ‘int main()’: user.cpp:18:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<=s.size();++i) ^ user.cpp:22:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=s.size();++i) ^ user.cpp:15:17: warning: unused variable ‘i’ [-Wunused-variable] int lit=0,cuv=0,i; ^