Compilare: user.cpp: In function ‘void BuildConvexHull()’: user.cpp:48:113: warning: comparison of constant ‘-1’ with boolean expression is always false [-Wbool-compare] if(Eq(v[i].first,v[best].first)==-1 || (!Eq(v[i].first,v[best].first) && Eq(v[i].second,v[best].second))==-1) best=i; ^ user.cpp: In function ‘int main()’: user.cpp:68:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("terenuri.in","r",stdin); ^ user.cpp:69:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("terenuri.out","w",stdout); ^ user.cpp:71:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:75:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf",&v[i].first,&v[i].second); ^ user.cpp:102:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf",&x,&y); ^