foo.cc: In function 'int main()':
foo.cc:48:7: warning: unused variable 'flag1' [-Wunused-variable]
   int flag1=0,flag2=0;
       ^~~~~
foo.cc:48:15: warning: unused variable 'flag2' [-Wunused-variable]
   int flag1=0,flag2=0;
               ^~~~~
foo.cc:15:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&T);
  ~~~~~^~~~~~~~~
foo.cc:18:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&N,&M);
   ~~~~~^~~~~~~~~~~~~~
foo.cc:23:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",square[i].a[j]+k);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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