Compilare: user.cpp: In function ‘int main()’: user.cpp:29:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cercuri4.in","r",stdin); ^ user.cpp:30:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cercuri4.out","w",stdout); ^ user.cpp:31:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&n); ^ user.cpp:33:66: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld %lld",&t[i].x,&t[i].y,&t[i].r,&t[i].v); ^