Compilare: user.cpp: In function ‘int main()’: user.cpp:13:18: warning: unused variable ‘k’ [-Wunused-variable] int n, i, j, k, t; ^ user.cpp:13:21: warning: variable ‘t’ set but not used [-Wunused-but-set-variable] int n, i, j, k, t; ^ user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prim.in","r",stdin); ^ 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("prim.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("%d",&n); ^