说明：  矩阵连乘问题 给定n个矩阵A1，A2，…，An，其中，Ai与Aj+1是可乘的，i=1，2，…，n-1。 你的任务是要确定矩阵连乘的运算次序，使计算这n个矩阵的连乘积A1A2…An时总的元素乘法次数达到最少。
(Matrixcontinuallymultiply problem Description of the problem Given n matrices A1, A2, ..., An, which , Ai and Aj 1 is multiplicative , i = 1,2, ..., n-1. Your task is to determine the order of the matrix continually multiply operation , make the calculation of these n matrices even when the product A1A2 ... An element of the total number of multiplications to a minimum. )