Compilare: user.cpp: In function ‘bool cmp(std::pair<double, double>, std::pair<double, double>)’: user.cpp:8:71: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] return (a.first <= b.first - 0.0001 || a.first < b.first + 0.0001 && a.second <= b.second - 0.0001); ^ user.cpp: In function ‘int main()’: user.cpp:12:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate3.in","r",stdin); ^ user.cpp:13:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate3.out","w",stdout); ^ user.cpp:14:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:16:49: 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); ^