Compilare: user.cpp: In function ‘int main()’: user.cpp:19:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("distanta.in", "r", stdin); ^ user.cpp:20:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("distanta.out", "w", stdout); ^ user.cpp:21:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%hi", &t); ^ user.cpp:23:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%Lf%Lf%Lf%Lf", &a, &b, &x0, &y0); ^