5 persons numbered 1 to 5 are standing in a row at 5 spots.
1 2 3 4 5
Any person can call another person among the remaining 4. When someone calls someone else, the person who was called comes on the adjacent spot toward his side, on the same side of the person that called him, and then the others rearrange themselves accordingly. (see example ahead)
Now the first and last spot are special. After each time someone calls someone else, subsequent to the rearrangement, the two persons standing on the first and last spot teleport to each others’ spots!
For example, if person 2 calls person 5, and after rearrangement and teleportation, person 1 calls person 4, these two steps can be represented in the following way:
They can’t call anyone who’s already adjacent to them of course, since they’re already on their side, and it won't be counted as a step.
What is the minimum number of steps that’ll take for the people for going
1 2 3 4 5
5 4 3 2 1
NOTE: I'm new at creating puzzles, I might have missed some important detail, so please bear with me. I'll try to respond promptly to the comments and make any required changes.