Compilare: user.cpp: In function ‘int main()’: user.cpp:16:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while((last=s2.find(s1.c_str(),last+1,sizee))!=string::npos) ^ user.cpp:19:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<pos.size() && i<1000;i++) ^