Compilare: user.cpp: In function ‘int main()’: user.cpp:65:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < c.size(); ++i) ^ user.cpp:36:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tdeque.in","r",stdin); ^ user.cpp:37:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tdeque.out","w",stdout); ^ user.cpp:39:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:43:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^