Compilare: user.cpp: In function ‘int main()’: user.cpp:14:9: warning: unused variable ‘j’ [-Wunused-variable] int i, j, n, a; ^ user.cpp:14:15: warning: unused variable ‘a’ [-Wunused-variable] int i, j, n, a; ^ user.cpp:11:35: 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:12:36: 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); ^