Compilare: user.cpp: In function ‘int main()’: user.cpp:25:29: warning: format ‘%Lf’ expects argument of type ‘long double’, but argument 2 has type ‘double’ [-Wformat=] printf("%.5Lf", area / 2); ^ user.cpp:5:35: 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:6:37: 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:10:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int N; scanf("%d %lf %lf", &N, &x0, &y0); ^ user.cpp:16:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf %lf", &x2, &y2); ^