Compilare: user.cpp: In function ‘int main()’: user.cpp:16:9: warning: variable ‘f1’ set but not used [-Wunused-but-set-variable] int f1,f2; ^ user.cpp:16:12: warning: variable ‘f2’ set but not used [-Wunused-but-set-variable] int f1,f2; ^ user.cpp:13:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sir.in","r",stdin); ^ user.cpp:14:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sir.out","w",stdout); ^ user.cpp:17:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&x,&y,&z); ^ user.cpp:20:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^