catalan大数的计算，用字符串实现，效率不太高-the calculation of catalan

产生Catalan数,火车调度的所有排列,以及证明排列的正确性. 迷宫算法.-produces Catalan number, and all permutation in train dispatch, and of course including the proof. maze algorithm

矩阵链乘： P=a1×a2×a3×……×an，依据乘法结合律，不改变其顺序，只用括号表示成对的乘积，试问有几种括号化的方案？(h(n)种) 出栈次序问题。-Matrix chain multiplication: P=a1* A2* A3*......* an, according to the multiplication with law, does not change the order, the brackets only representation of the pairwis