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("ktown.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("ktown.out","w",stdout); ^ user.cpp:23:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %lld",&n,&k); ^ user.cpp:24:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) {scanf("%lld",&a[i]);a[i]-=(1LL*i-1LL)*k;srt[i]=a[i];} ^