Compilare: main.cpp: In constructor 'stringWrapper::stringWrapper(std::__cxx11::string&)': main.cpp:29:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size() / 9; i++) { ~~^~~~~~~~~~~~~~ main.cpp: In member function 'bool stringWrapper::operator<(const stringWrapper&) const': main.cpp:44:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int idx = 0; idx < numbers.size(); idx++) { ~~~~^~~~~~~~~~~~~~~~ main.cpp: In member function 'void stringWrapper::printUnderlyingString()': main.cpp:74:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int idx = 0; idx < numbers.size(); idx++) { ~~~~^~~~~~~~~~~~~~~~ main.cpp:75:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (idx < numbers.size() - 1) { ~~~~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:209:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("nums.in", "r", stdin); ^ main.cpp:210:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("nums.out", "w", stdout); ^