Ito Hiro   Teruyama Junichi   Yoshida Yuichi   
電子情報通信学会技術研究報告. COMP, コンピュテーション 109(391) 45-49 2010年1月
We investigate the following sorting puzzle: We are given n bins with two balls in each bin. Balls in the ith bin are numbered n-i+1. We can swap two balls from adjacent bins. How many number of swaps are needed in order to sort balls, i.e., move ...