Compilare: user.cpp: In function ‘int main()’: user.cpp:5:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("cal.in","r",stdin); freopen("cal.out","w",stdout); ^ user.cpp:5:61: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("cal.in","r",stdin); freopen("cal.out","w",stdout); ^ user.cpp:6:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&x,&y,&s,&n); ^ user.cpp:8:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] { scanf("%d%d",&a,&b);if (abs(x-a)+abs(y-b)==s) f++;}printf("%d\n",f); ^