foo.cc: In function 'int main()':
foo.cc:22:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:25:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a[i][j]);
    ~~~~~^~~~~~~~~~~~~~~
foo.cc: In function 'void dfs(int, int)':
foo.cc:16:40: warning: 'yy2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   f[q][p]=f[q][x]+(abs(xx1-xx2)+abs(yy1-yy2))*(abs(xx1-xx2)+abs(yy1-yy2));
                                     ~~~^~~~
foo.cc:16:40: warning: 'yy1' may be used uninitialized in this function [-Wmaybe-uninitialized]
foo.cc:16:27: warning: 'xx2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   f[q][p]=f[q][x]+(abs(xx1-xx2)+abs(yy1-yy2))*(abs(xx1-xx2)+abs(yy1-yy2));
                        ~~~^~~~
foo.cc:16:27: warning: 'xx1' may be used uninitialized in this function [-Wmaybe-uninitialized]

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