foo.cc: In function 'bool cmp(Point, Point)':
foo.cc:17:32: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
     return a.x<b.x || a.x==b.x && a.y<b.y;
                       ~~~~~~~~~^~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:37:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ~~~~~^~~~~~~~~
foo.cc:38:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (int i=0;i<n;i++)scanf("%lf%lf",&p[i].x,&p[i].y);
                          ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

自豪的采用 HydroJudger 进行评测(github.com/hydro-dev/HydroJudger)

{"receive":"2020-06-23T04:04:32.037Z","handle":"2020-06-23T04:04:32.037Z","cache_start":"2020-06-23T04:04:32.045Z","read_cases":"2020-06-23T04:04:32.165Z","judge":"2020-06-23T04:04:32.166Z","done":"2020-06-23T04:04:34.182Z"}