Compilare: user.cpp: In function ‘int main()’: user.cpp:19:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.in" , "r" , stdin) ; ^ user.cpp:21:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n) ; //f >> n ; ^ user.cpp:24:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf %lf" , &v[i].x , &v[i].y) ; //f >> v[i].x >> v[i].y ; ^