Assuming all the posts are in a line you can lay out your tiles so a joint comes on one side of the posts then you will only have to cut a "L" or "U" shape out of the tiles on the other side.

If you lay the tiles to suit the overall room you may end up with a post in the middle of a tile which means having to split a tile in half and cut out part of the post in either half. Or cut strips of tile to make a border around each post ie if your joints stop 50mm from one edge of the post cut four 50mm strips of tile to lay around the post then treat as the first option.

JAson