Compilare: user.cpp: In function ‘int main()’: user.cpp:40:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<answer.size();i++) ^ user.cpp:16:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xmoto.in","r",stdin); ^ user.cpp:17:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xmoto.out","w",stdout); ^ user.cpp:20:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%lf",&n,&l); ^ user.cpp:22:73: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf%lf%lf%lf",&v[i].a,&v[i].b,&v[i].k,&v[i].q,&v[i].v); ^