Compilare: user.cpp: In function ‘void Back(int)’: user.cpp:40:17: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (Valid(k)) ^ user.cpp: In function ‘int main()’: user.cpp:53:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("damesah.in","r",stdin); ^ user.cpp:54:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("damesah.out","w",stdout); ^ user.cpp:55:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^