Compilare: user.cpp: In function ‘int main()’: user.cpp:10:35: 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:11:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.out", "w", stdout); ^ user.cpp:16:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n);//cin >> n; ^ user.cpp:17:50: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf %lf", &start.first, &start.second);//cin >> start.first >> start.second; ^ user.cpp:21:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf %lf", &points[1].first, &points[1].second);//cin >> points[1].first >> points[1].second; ^