Compilare: user.cpp: In function ‘int main()’: user.cpp:2:111: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;ifstream f("scalecrop.in");double x,y,z,w,r;int main(){freopen("scalecrop.out","w",stdout);f>>x>>y>>z>>w;r=max(x/z,y/w);printf("%f %f",z*r,w*r);} ^