Compilare: user.cpp: In function ‘int main()’: user.cpp:14:14: warning: unused variable ‘a’ [-Wunused-variable] int op,x,a; ^ user.cpp:11:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.in","r",stdin); ^ 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("hashuri.out","w",stdout); ^ user.cpp:16:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&n); ^ user.cpp:19:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i",&op,&x); ^