Compilare: user.cpp: In function ‘int main()’: user.cpp:21:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qtri.in","r",stdin); ^ user.cpp:22:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qtri.out","w",stdout); ^ user.cpp:24:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&tests); ^ user.cpp:26:74: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d%d%d%d",&a.x,&a.y,&b.x,&b.y,&c.x,&c.y,&d.x,&d.y); ^