Compilare: user.cpp: In function ‘int Stoi(std::string)’: user.cpp:10:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:53:5: warning: ‘nr’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(nr==t) ^