有些排列组合问题,直接考虑不易解决,分类讨论又十分麻烦,若通过转化角度,将其转化为等价的问题,不但能拓展思路,还能避繁就简,化难为易。下面对化归思想在排列、组合中的应用作简单的策略分析,供同学们参考。 Some permutation and combination problems are not easily solved directly and the discussion of classification is very troublesome. If we transform it into an equivalent problem through transformation, not only can we broaden our thinking, but also we can avoid difficulties and make things difficult. Following the return to ideology in the arrangement, the combination of simple strategic analysis for the students reference.