Compilare: user.cpp: In function ‘void solve()’: user.cpp:152:17: warning: unused variable ‘x’ [-Wunused-variable] int x = a[i].x, y = a[i].y; ^ user.cpp:152:29: warning: unused variable ‘y’ [-Wunused-variable] int x = a[i].x, y = a[i].y; ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:21:38: 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); ^