Compilare: main.cpp: In member function 'int Read::nextInt()': main.cpp:24:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos >= s.size()) { ~~~~^~~~~~~~~~~ main.cpp:30:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < s.size() && isdigit (s[pos])) { ~~~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:46:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("secventa.out", "w", stdout); ^