The smell isn't just from the air, it gets onto everything in the room. An air purifier isn't going to remove that smell from the room.

Also, any air purifier that can absorb the smell also will not last long. Probably 1-2 times clean your room and the carbon filters will be full already and you have to buy new one.

You can't escape physics and chemistry

Even hard surfaces can absorb smell. Still need to manually clean/wipe often to prevent smell from setting in.

Ventilation is the better solution. Yes it will reduce your air cond efficiency, but it will reduce the amount of smoke your aircond and purifier have to handle. Don't forget that the smoke also gets into your aircond.

If possible, set up your room such that you have a spot for smoking that is closest to an exhaust ventilation. Then set the air purifier to be at a spot away from it to catch any stray smoke and blow clean air up to the aircond to use.