Compilare: user.cpp: In function ‘int main()’: user.cpp:28:37: 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:29:39: 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:31:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:33:58: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&v[i].x,&v[i].y,&v[i].r,&v[i].f); ^