Combinations and Permutations - Math is Fun There are basically two types of permutation: Repetition is Allowed: such as the lock above It could be "333" No Repetition: for example the first three people in a running race You can't be first and second 1 Permutations with Repetition These are the easiest to calculate When a thing has n different types we have n choices each time!
排列(组合数学术语)_百度百科 重复排列 (permutation with repetition [2])是一种特殊的排列。 从n个不同元素中可重复地选取m个元素。 按照一定的顺序排成一列,称作从n个元素中取m个元素的可重复排列。 当且仅当所取的元素相同,且元素的排列顺序也相同,则两个排列相同。
置换和排列 - OI Wiki 一个集合 到自身的双射(即一一对应) 称为 的一个 置换 (permutation)。 如果集合 上还具有 全序 关系,则它的一个置换也常称作一个 (全)排列。
Permutation - Math. net A permutation refers to a selection of objects from a set of objects in which order matters A phone number is an example of a ten number permutation; it is drawn from the set of the integers 0-9, and the order in which they are arranged in matters
Permutations and combinations | Description, Examples, Formula . . . permutations and combinations, the various ways in which objects from a set may be selected, generally without replacement, to form subsets This selection of subsets is called a permutation when the order of selection is a factor, a combination when order is not a factor
Permutations | Brilliant Math Science Wiki In combinatorics, a permutation is an ordering of a list of objects For example, arranging four people in a line is equivalent to finding permutations of four objects More abstractly, each of the following is a permutation of the letters
Permutation -- from Wolfram MathWorld A permutation, also called an "arrangement number" or "order," is a rearrangement of the elements of an ordered list S into a one-to-one correspondence with S itself The number of permutations on a set of n elements is given by n! (n factorial; Uspensky 1937, p 18)