foo.cc: In function 'int main()':
foo.cc:54:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&T);
     ~~~~~^~~~~~~~~
foo.cc:56:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&n);
         ~~~~~^~~~~~~~~
foo.cc:57:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         for(int i=1;i<=n;i++) for(int j=1;j<=n;j++) scanf("%d",&d[i][j]);
                                                     ~~~~~^~~~~~~~~~~~~~~

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