Compilare: user.cpp: In function ‘int main()’: user.cpp:69:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("geometry.in","r",stdin); ^ user.cpp:70:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("geometry.out","w",stdout); ^ user.cpp:72:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:74:88: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i=1;i<=n;i++) scanf("%d %d %d %d",&t[i].a.x,&t[i].a.y,&t[i].b.x,&t[i].b.y); ^