/in/foo.cc: In function 'void dfs(int, int, int)':
/in/foo.cc:24:14: error: 'dx' was not declared in this scope
   int newx=x+dx[i];
              ^~
/in/foo.cc:24:14: note: suggested alternative: 'x'
   int newx=x+dx[i];
              ^~
              x
/in/foo.cc:25:14: error: 'dy' was not declared in this scope
   int newy=y+dy[i];
              ^~
/in/foo.cc:25:14: note: suggested alternative: 'y'
   int newy=y+dy[i];
              ^~
              y