Compilare: user.cpp: In function ‘int main()’: user.cpp:20:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("findmin.in","r",stdin); ^ user.cpp:21:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("findmin.out","w",stdout); ^ user.cpp:23:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:27:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;++i) scanf("%d",&a[i]),update(a[i],i); ^