Compilare: user.cpp: In function ‘int main()’: user.cpp:20:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(dq.empty() || dq.size() == N) { ^ user.cpp:11:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("weeee.in", "r", stdin); ^ user.cpp:13:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("weeee.out", "w", stdout); ^ user.cpp:14:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &N); ^ user.cpp:15:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s); ^