Compilare: user.cpp: In function ‘int main()’: user.cpp:86:36: 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:87:38: 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:89:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &q); ^ user.cpp:90:106: 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", &X[i]), go[i] = i + 1, ord.pb(i), dl[i] = i, dr[i] = n - i + 1; ^ user.cpp:91:83: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i = 1; i <= q; i++) scanf("%lld%lld", &Q[i].pos, &Q[i].disc), Q[i].id = i;; ^