Compilare: user.cpp: In function ‘std::string max_lexic(std::string)’: user.cpp:84:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i(2); i < s.size() - 1; i++) { ^ user.cpp:101:11: warning: statement has no effect [-Wunused-value] for (p; p < s.size() - 1; p++) ^ user.cpp:101:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (p; p < s.size() - 1; p++) ^ user.cpp: In function ‘int main()’: user.cpp:125:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i(1); i < rez.size(); i++) ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:9:47: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:39:51: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^