Compilare: main.cpp: In function 'int main()': main.cpp:41:34: warning: format '%lf' expects argument of type 'double', but argument 2 has type 'long double' [-Wformat=] printf("%.5lf", fabs(ans * 0.5)); ^ main.cpp:20:33: 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); ^ main.cpp:21:35: 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); ^ main.cpp:24:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:27:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf", &x, &y); ^