假设停在铁路调度站入口处的车厢序列的编号依次为1，2，3，...n。设计一个程序，求出所有可能由此输出的长度为n的车厢序列。-Assuming stopped at the the railway dispatch station entrance compartment sequence numbered 1,2,3, ... n. Design a program determined all possible thereby outputting compartments sequence of length n.