Compilare: main.cpp: In function 'int main()': main.cpp:109:43: warning: format '%lf' expects argument of type 'double', but argument 2 has type '__gnu_cxx::__alloc_traits<std::allocator<long double> >::value_type {aka long double}' [-Wformat=] printf("%.7lf\n", angles[i] - 0.0001); ^ main.cpp:28:8: warning: variable 'inv' set but not used [-Wunused-but-set-variable] auto inv = [&] (ld ang) { ^~~ main.cpp:14:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("laser.in", "r", stdin); ^ main.cpp:15:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("laser.out", "w", stdout); ^ main.cpp:38:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:43:65: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &v[i].x1, &v[i].y1, &v[i].x2, &v[i].y2); ^ main.cpp:66:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &col); ^ main.cpp: In lambda function: main.cpp:84:3: warning: control reaches end of non-void function [-Wreturn-type] }; ^