Compilare: user.cpp: In function ‘int main()’: user.cpp:5:12: warning: unused variable ‘f’ [-Wunused-variable] int n,i,j,f,a; ^ user.cpp:5:14: warning: unused variable ‘a’ [-Wunused-variable] int n,i,j,f,a; ^ user.cpp:6:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xspe.in","r",stdin); ^ user.cpp:7:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xspe.out","w",stdout); ^ user.cpp:8:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:10:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^