Compilare: user.cpp: In function ‘int main()’: user.cpp:13:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spider-man.in", "r", stdin); ^ user.cpp:14:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spider-man.out", "w", stdout); ^ user.cpp:15:69: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf%lf%lf%lf%lf%lf", &xc, &yc, &r, &x1, &y1, &x2, &y2); ^