Compilare: user.cpp: In function ‘int main()’: user.cpp:16:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("melc.in","r",stdin); ^ user.cpp:17:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("melc.out","w",stdout); ^ user.cpp:19:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf",&a[0].x,&a[0].y);a[0].ind=0; ^ user.cpp:20:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:23:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf%d",&a[i].x,&a[i].y,&a[i].ind); ^