Compilare: user.cpp: In function ‘bool memo(int)’: user.cpp:16:31: warning: suggest parentheses around arithmetic in operand of ‘|’ [-Wparentheses] ans&=memo(mask^(1<<i)|(1<<pr)); ^ user.cpp: In function ‘int main()’: user.cpp:25:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coins.in","r",stdin); ^ user.cpp:26:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coins.out","w",stdout); ^ user.cpp:27:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:36:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^