Package org.aoju.bus.core.math

Class Combine

java.lang.Object

org.aoju.bus.core.math.Combine

public class Combine
extends Object

组合,即C(n, m) 组合相关类

Since:

Java 17+

Author:

Kimi Liu

Constructor Summary

Constructors

Constructor	Description
Combine(String[] datas)	组合,即C(n, m) 排列组合相关类

Method Summary

Modifier and Type	Method	Description
static long	count(int n, int m)	计算组合数,即C(n, m) = n!
static long	countAll(int n)	计算组合总数,即C(n, 1) + C(n, 2) + C(n, 3)...
List<String[]>	select(int m)	组合选择(从列表中选择m个组合)
List<String[]>	selectAll()	全组合

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Combine

public Combine(String[] datas)

组合,即C(n, m) 排列组合相关类

Parameters:

datas - 用于组合的数据

Method Details

count

public static long count(int n,
 int m)

计算组合数,即C(n, m) = n!/((n-m)! * m!)

Parameters:

n - 总数

m - 选择的个数

Returns:

组合数

countAll

public static long countAll(int n)

计算组合总数,即C(n, 1) + C(n, 2) + C(n, 3)...

Parameters:

n - 总数

Returns:

组合数

select

public List<String[]> select(int m)

组合选择(从列表中选择m个组合)

Parameters:

m - 选择个数

Returns:

组合结果

selectAll

public List<String[]> selectAll()

全组合

Returns:

全排列结果