foo.cc: In function 'void init()':
foo.cc:37:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d",&n);
 ~~~~~^~~~~~~~~
foo.cc:39:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 for(int j=1;j<=n+1;j++) scanf("%lf",&a[i][j]);
                         ~~~~~^~~~~~~~~~~~~~~~

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

{"receive":"2020-08-07T13:20:11.052Z","handle":"2020-08-07T13:20:11.052Z","cache_start":"2020-08-07T13:20:11.059Z","read_cases":"2020-08-07T13:20:11.184Z","judge":"2020-08-07T13:20:11.185Z","done":"2020-08-07T13:20:12.377Z"}