Compilare: user.cpp: In function ‘int main()’: user.cpp:16:16: warning: unused variable ‘v1’ [-Wunused-variable] double A,B,v1,v2; ^ user.cpp:16:19: warning: unused variable ‘v2’ [-Wunused-variable] double A,B,v1,v2; ^ user.cpp:12:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tictac.in","r",stdin); ^ user.cpp:13:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tictac.out","w",stdout); ^ user.cpp:17:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&T); ^ user.cpp:20:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf",&A,&B); ^