The bottom line of a 2×13 rectangle is filled with 13 tokens marked with the numbers 1,2,...,13 and located in that order. An operation is a move of a token from its cell into a free adjacent cell (two cells are called adjacent if they have a common side). What is the minimum number of operations needed to rearrange the chips in reverse order in the bottom line of the rectangle? combinatoricsgridsOperationoptimizationcombinatorics solvedSwapordering