Compilare: user.cpp: In function ‘int main()’: user.cpp:61:34: warning: unused variable ‘j’ [-Wunused-variable] int i , vf , x , y , V , t , j; ^ user.cpp:63:26: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(IN,"r",stdin); ^ user.cpp:64:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(OUT,"w",stdout); ^ user.cpp:66:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d" , &n , &m ); ^ user.cpp:69:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , &a[i] ); ^ user.cpp:74:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , &V ); ^ user.cpp:75:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d" , &x , &y ); ^