说明：  商人过河问题是数学建模中的一个经典问题，程序利用链表存储渡河状态，使用穷举的算法实现。该算法会找出N个商人/随从渡河的一个可行方案，但并不保证是最佳方案。写完这个程序后让我想到的居然是图的深度优先搜索，二者在查找的思想上是类似的。
(Merchants across the river mathematical modeling problem is a classic problem, the use of list storage procedures to cross the river, and the use of exhaustive algorithm. The algorithm will identify a businessman N/entourage to cross the river is a feasible option, but not guaranteed to be the best option. Finished after this procedure so that I can think of is actually the depth-first search graph, both ideologically and in looking for are similar.)