Compilare: user.cpp: In function ‘int main()’: user.cpp:110:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( stk.size() > aux && ccw( make_pair( get<0>(pts[stk[stk.size() - 2]]), get<1>(pts[stk[stk.size() - 2]]) ), ^ user.cpp:125:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( stk.size() > aux && ccw( make_pair( get<0>(pts[stk[stk.size() - 2]]), get<1>(pts[stk[stk.size() - 2]]) ), ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:14:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^