Found this interesting problem. See if you can solve this…
Four tanks going in a line on a very narrow bridge encounter four friendly tanks in a line coming from the other side. Unfortunately, they see each other only when there is exactly one tank worth of distance between the two leading tanks from either side. And there is no space on the bridge to go around each other.

Now here is a problem – None of the tanks can reverse. However, a tank can climb over another tank as long as there is space for the tank to land on the bridge after climbing over a tank. A tank cannot climb over more than one tank at a time. (meaning it has to come down to the bridge after climbing one tank). Also no tank can take the weight of more one one tank on top of it. (meaning you cannot have three tanks on top of each other).

How can the two sets of four tanks sort out the problem and eventually proceed their own way?