org.nutz.lang

类 Maths

java.lang.Object

org.nutz.lang.Maths

public abstract class Maths
extends Object

A group of helper functions to counting some ...

作者:

zozoh(zozohtnt@gmail.com), pw

构造器概要

构造器

构造器和说明
Maths()

方法概要

限定符和类型	方法和说明
static int	bit(String s) Convert a binary string to a integer
static int	extract(int bs, int low, int high) Get part of one integer as a new integer
static boolean	isMask(int bs, int mask) Test current bit is match the given mask at least one bit or not.
static boolean	isMaskAll(int bs, int mask) Test current bit is all match the give mask.
static boolean	isNoMask(int bs, int mask)
static int	max(int... nums) 返回最大的一个
static int	min(int... nums) 返回最小的一个
static String[]	permutation(char... arr) 获得字符数组的全排列
static String[]	permutation(int length, char... arr) 按照指定长度, 获得字符数组的全排列

从类继承的方法 java.lang.Object

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

构造器详细资料

Maths

public Maths()

方法详细资料

max

public static int max(int... nums)

返回最大的一个

参数:

nums - 需要比较的数组

返回:

最大值

min

public static int min(int... nums)

返回最小的一个

参数:

nums - 需要比较的数组

返回:

最小值

bit

public static int bit(String s)

Convert a binary string to a integer

参数:

s - binary string

返回:

integer

isMask

public static boolean isMask(int bs,
                             int mask)

Test current bit is match the given mask at least one bit or not.

参数:

bs - integer, bit map

mask - another bit map

返回:

if one of bit value is '1' in mask, and it is also is '1' in bs return true, else false

isNoMask

public static boolean isNoMask(int bs,
                               int mask)

isMaskAll

public static boolean isMaskAll(int bs,
                                int mask)

Test current bit is all match the give mask.

参数:

bs - integer, bit map

mask - another bit map

返回:

if all bit value is '1' in mask, and it is also is '1' in bs return true, else false

extract

public static int extract(int bs,
                          int low,
                          int high)

Get part of one integer as a new integer

参数:

bs - original integer

low - the low bit position (inclusive), 0 base

high - the hight bit position (exclusive), 0 base

返回:

new integer

permutation

public static String[] permutation(char... arr)

获得字符数组的全排列

参数:

arr - 字符数组

返回:

全排列

permutation

public static String[] permutation(int length,
                                   char... arr)

按照指定长度, 获得字符数组的全排列

参数:

arr - 字符数组

返回:

全排列