Compilare: user.cpp: In function ‘int period(int)’: user.cpp:15:23: warning: right operand of comma operator has no effect [-Wunused-value] per=1,prv=numb,act,l=1; ^ user.cpp: In function ‘int main()’: user.cpp:50:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.in","r",stdin); ^ user.cpp:51:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.out","w",stdout); ^ user.cpp:52:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&lenght); ^ user.cpp:54:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^