Compilare: user.cpp:9:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){ ^ user.cpp: In function ‘int main()’: user.cpp:16:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++){ ^ user.cpp:19:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<t.size();j++) ^