Compilare: user.cpp: In function ‘int main()’: user.cpp:83:22: warning: format ‘%lf’ expects argument of type ‘double’, but argument 2 has type ‘long double’ [-Wformat=] printf("%.8lf\n", x); ^ user.cpp:57:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( FILE_IN, "r", stdin ); ^ user.cpp:58:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( FILE_OUT, "w", stdout ); ^ user.cpp:62:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:66:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld %ld %ld", &a, &b, &x0, &y0); ^