foo.cc: In function ‘void dfs(int, int, int)’:
foo.cc:10:9: error: ‘a’ was not declared in this scope
   10 |         a[x][y]=dep;
      |         ^
foo.cc: In function ‘int main()’:
foo.cc:28:31: error: ‘a’ was not declared in this scope
   28 |                         cout<<a[i][j]<<' ';
      |                               ^