Compilare: user.cpp: In function ‘int main()’: user.cpp:23:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamster.in","r",stdin); ^ user.cpp:24:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamster.out","w",stdout); ^ user.cpp:28:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &q); ^ user.cpp:29:43: 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]); ^ user.cpp:31:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %lld", &x, &y); ^