众所周知,排列组合问题由于其思想方法独特,计算量庞大,对结果的检验困难等等,所以在解决这类问题时需要我们遵循一定的优先顺序,如特殊元素优先、特珠位置优先、先选后排、先分组后分配等等.本文所谈的是两个具体问题,如果对本没 As we all know, the problem of permutation and combination is due to its unique method of thinking, large amount of calculation, difficulty in testing the results, etc. Therefore, we need to follow certain priorities in solving such problems, such as special element priority, special bead position first, and first selection. The back row, the first group after the distribution and so on. This article talks about two specific issues, if not