Compilare: main.cpp: In function 'int main()': main.cpp:43:28: warning: format '%lf' expects argument of type 'double', but argument 2 has type 'long double' [-Wformat=] printf("%lf", -area / 2); ^ main.cpp:45:27: warning: format '%lf' expects argument of type 'double', but argument 2 has type 'long double' [-Wformat=] printf("%lf", area / 2); ^ 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:26:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lf %lf", &d1, &d2); ^