Compilare: main.cpp: In function 'int main()': main.cpp:101:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < x1.size(); ++j) ~~^~~~~~~~~~~ main.cpp:104:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < x2.size(); ++j) ~~^~~~~~~~~~~ main.cpp: In function 'int Var(std::__cxx11::string&)': main.cpp:70:12: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized] return t; ^