Compilare: user.cpp: In function ‘bool cmp(std::string, std::string)’: user.cpp:33:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();++i) ^ user.cpp:35:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();++i) ^ user.cpp:37:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=min(a.size(),b.size());++i) ^ user.cpp:32:10: warning: variable ‘A’ set but not used [-Wunused-but-set-variable] char A[35],B[35]; ^ user.cpp:32:16: warning: variable ‘B’ set but not used [-Wunused-but-set-variable] char A[35],B[35]; ^ user.cpp: In function ‘void query(std::string)’: user.cpp:84:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:144:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<x.size();++j) ^