生成行列式的项数的全排列，例如3阶行列式的项数的全排列为123,132,213,231,312,321，这些排列中每一种都是指向行列式某一项的下标。-Generate the determinant of the number of items arranged, such as third-order determinant of the number of items arranged 123,132,213,231,312,321, each of these permutations are pointing to the determinant of a subscr ipt