mid-14c., from Old French permutacion "change, shift" (14c.), from Latin permutationem (nominative permutatio) "a change, alteration, revolution," noun of action from past participle stem of permutare "change thoroughly, exchange," from per- "thoroughly" (see per) + mutare "to change" (see mutable).
中文解释
在数学的排列与组合中用 A 代表 Arrangement 表示“排列”（在旧教材为 P -> Permutation），用 C 代表 Combination 表示“组合”，所以如果你还记得排列与组合的计算公式的话，就一目了然了。
实用例句
1. Every sort of permutation and combination is possible in human nature.
火的本性可能有各种交织和组合的情况.
来自辞典例句
2. Such a permutation is called a derangement.
这样的一个排列称为错位排列.
来自辞典例句
3. Other enumeration problems lead us to the study of orbits of permutation groups.
其它的计数问题引导我们去研究置换群的轨道.
来自辞典例句
4. The permutation is even if the number of inversions it contains is even.
如果一个排列中含有的反序的个数是偶数,则称它为偶排列.
来自辞典例句
5. Unique because that particular permutation has not appeared before.
