Compilare: user.cpp: In function ‘int one(int)’: user.cpp:10:20: warning: suggest parentheses around arithmetic in operand of ‘|’ [-Wparentheses] return (arg<<1)&mask|1; ^ user.cpp: In function ‘int main()’: user.cpp:38:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biti.in", "r", stdin); ^ user.cpp:39:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biti.out", "w", stdout); ^ user.cpp:40:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^