Compilare: user.cpp: In function ‘int main()’: user.cpp:23:63: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (top < x && !st.empty() && st.size() + N - i + 1 >= M) { ^ user.cpp:12:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("trompeta.in", "r", stdin); ^ user.cpp:13:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("trompeta.out", "w", stdout); ^ user.cpp:16:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &N, &M); ^ user.cpp:19:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%1d", &x); ^