Compilare: user.cpp:11:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){ ^ user.cpp: In function ‘int main()’: user.cpp:21:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<t.size();i++){ ^ user.cpp:27:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++){ ^