Compilare: user.cpp: In function ‘int main()’: user.cpp:66:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("jjoe.in","r",stdin); ^ user.cpp:67:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("jjoe.out","w",stdout); ^ user.cpp:69:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld%lld", &a, &b, &p, &k); ^