Compilare: main.cpp: In function 'std::__cxx11::string XOR(std::__cxx11::string)': main.cpp:41:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < str.size(); i++) { ~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:88:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < ans.size() - 1; i++) { ~~^~~~~~~~~~~~~~~~