javaa算法代码

A. Apriori算法的java实现的代码是什么

哥们儿，有点长哦，好像传不上来

B. Java用查找算法的一段代码如下： 其中boolean A=false; if(name.equals(arr[i])) 麻烦解释一下 尽量直白

数组从第一个开始比较，完全相同（当前数组值和输入值一模一样）A就赋值为true；不一样A的值不变

C. 用JAVA语言在网页里实现加减乘除算法的源代码要怎么写吖！

如果要用java语言在网页实现的话：
那网页必须是JSP
<%
java code
%>
这样就ok了

D. 求一个java逆波兰算法的代码,要带输入框.就是可以根据输入框的内容用逆波兰算法求出答案.

已发送。多加点分哈
import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Label;
import java.awt.TextField;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.StringTokenizer;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

//栈类
class Stacks {
private LinkedList list = new LinkedList();
int top = -1;

public void push(Object value) {
top++;
list.addFirst(value);
}

public Object pop() {
Object temp = list.getFirst();
top--;
list.removeFirst();
return temp;

}

public Object top() {
return list.getFirst();
}
}

class Expression {
private ArrayList expression = new ArrayList();// 存储中序表达式

private ArrayList right = new ArrayList();// 存储右序表达式

private String result;// 结果

// 依据输入信息创建对象，将数值与操作符放入ArrayList中
Expression(String input) {
StringTokenizer st = new StringTokenizer(input, "+-*/()", true);
while (st.hasMoreElements()) {
String s = st.nextToken();
expression.add(s);
}
}

// 将中序表达式转换为右序表达式
private void toRight() {
Stacks aStack = new Stacks();
String operator;
int position = 0;
while (true) {
if (Calculate.isOperator((String) expression.get(position))) {
if (aStack.top == -1
|| ((String) expression.get(position)).equals("(")) {
aStack.push(expression.get(position));
} else {
if (((String) expression.get(position)).equals(")")) {
while (true) {

if (aStack.top != -1
&& !((String) aStack.top()).equals("(")) {
operator = (String) aStack.pop();
right.add(operator);
} else {
if (aStack.top != -1)
aStack.pop();
break;
}
}
} else {
while (true) {
if (aStack.top != -1
&& Calculate.priority((String) expression
.get(position)) <= Calculate
.priority((String) aStack.top())) {
operator = (String) aStack.pop();
if (!operator.equals("("))
right.add(operator);
} else {
break;
}

}
aStack.push(expression.get(position));
}
}
} else
right.add(expression.get(position));
position++;
if (position >= expression.size())
break;
}
while (aStack.top != -1) {
operator = (String) aStack.pop();
if (!operator.equals("("))
right.add(operator);
}
}

// 对右序表达式进行求值
String getResult() {
String str = "";
this.toRight();
for (int i = 0; i < right.size(); i++) {
System.out.println(right.get(i));
}
Stacks aStack = new Stacks();
String op1, op2, is = null;
Iterator it = right.iterator();

while (it.hasNext()) {
is = (String) it.next();
if (Calculate.isOperator(is)) {
op1 = (String) aStack.pop();
op2 = (String) aStack.pop();
aStack.push(Calculate.twoResult(is, op1, op2));
} else
aStack.push(is);
}
result = (String) aStack.pop();
it = expression.iterator();
while (it.hasNext()) {
str += (String) it.next();
}
str += "\n=" + result;
return str;
}

}
class Calculate {
// 判断是否为操作符号
public static boolean isOperator(String operator) {
if (operator.equals("+") || operator.equals("-")
|| operator.equals("*") || operator.equals("/")
|| operator.equals("(") || operator.equals(")"))
return true;
else
return false;
}

// 设置操作符号的优先级别
public static int priority(String operator) {
if (operator.equals("+") || operator.equals("-"))
return 1;
else if (operator.equals("*") || operator.equals("/"))
return 2;
else
return 0;
}

// 做2值之间的计算
public static String twoResult(String operator, String a, String b) {
try {
String op = operator;
String rs = new String();
double x = Double.parseDouble(b);
double y = Double.parseDouble(a);
double z = 0;
if (op.equals("+"))
z = x + y;
else if (op.equals("-"))
z = x - y;
else if (op.equals("*"))
z = x * y;
else if (op.equals("/"))
z = x / y;
else
z = 0;
return rs + z;
} catch (NumberFormatException e) {
System.out.println("input has something wrong!");
return "Error";
}
}
}

public class Test extends JFrame {
JTextField exprss;
JLabel rlt;
JButton button;

public Test() {
this.setSize(500, 200);// 设置大小
this.setTitle("第一个JFrame的窗体!"); // 设置标题处的文字
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 窗体关闭时的操作 退出程序

double width = Toolkit.getDefaultToolkit().getScreenSize().width; // 得到当前屏幕分辨率的高
double height = Toolkit.getDefaultToolkit().getScreenSize().height;// 得到当前屏幕分辨率的宽
this.setLocation((int) (width - this.getWidth()) / 2,
(int) (height - this.getHeight()) / 2); // 设置窗体居中显示
this.setResizable(false);// 禁用最大化按钮
JPanel contentPane = (JPanel) this.getContentPane();
contentPane.setLayout(new FlowLayout());
exprss = new JTextField(10);
rlt = new JLabel();
rlt.setSize(200, 20);
button = new JButton("计算");
contentPane.add(exprss);
contentPane.add(button);
contentPane.add(rlt);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
String input = exprss.getText().trim();
Expression boya = new Expression(input);
String str = boya.getResult();
rlt.setText(str);
} catch (Exception ex) {
rlt.setText("Wrong input!!!");
}
}
});
}

public static void main(String avg[]) {
Test test = new Test();
test.setVisible(true);
}
}

E. java的md5的加密算法代码

import java.lang.reflect.*;

/*******************************************************************************
* keyBean 类实现了RSA Data Security, Inc.在提交给IETF 的RFC1321中的keyBean message-digest
* 算法。
******************************************************************************/
public class keyBean {
/*
* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的， 这里把它们实现成为static
* final是表示了只读，切能在同一个进程空间内的多个 Instance间共享
*/
static final int S11 = 7;

static final int S12 = 12;

static final int S13 = 17;

static final int S14 = 22;

static final int S21 = 5;

static final int S22 = 9;

static final int S23 = 14;

static final int S24 = 20;

static final int S31 = 4;

static final int S32 = 11;

static final int S33 = 16;

static final int S34 = 23;

static final int S41 = 6;

static final int S42 = 10;

static final int S43 = 15;

static final int S44 = 21;

static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0 };

/*
* 下面的三个成员是keyBean计算过程中用到的3个核心数据，在原始的C实现中 被定义到keyBean_CTX结构中
*/
private long[] state = new long[4]; // state (ABCD)

private long[] count = new long[2]; // number of bits, molo 2^64 (lsb

// first)

private byte[] buffer = new byte[64]; // input buffer

/*
* digestHexStr是keyBean的唯一一个公共成员，是最新一次计算结果的 16进制ASCII表示.
*/

public String digestHexStr;

/*
* digest,是最新一次计算结果的2进制内部表示，表示128bit的keyBean值.
*/
private byte[] digest = new byte[16];

/*
* getkeyBeanofStr是类keyBean最主要的公共方法，入口参数是你想要进行keyBean变换的字符串
* 返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
*/
public String getkeyBeanofStr(String inbuf) {
keyBeanInit();
keyBeanUpdate(inbuf.getBytes(), inbuf.length());
keyBeanFinal();
digestHexStr = "";
for (int i = 0; i < 16; i++) {
digestHexStr += byteHEX(digest[i]);
}
return digestHexStr;
}

// 这是keyBean这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数
public keyBean() {
keyBeanInit();
return;
}

/* keyBeanInit是一个初始化函数，初始化核心变量，装入标准的幻数 */
private void keyBeanInit() {
count[0] = 0L;
count[1] = 0L;
// /* Load magic initialization constants.
state[0] = 0x67452301L;
state[1] = 0xefcdab89L;
state[2] = 0x98badcfeL;
state[3] = 0x10325476L;
return;
}

/*
* F, G, H ,I 是4个基本的keyBean函数，在原始的keyBean的C实现中，由于它们是
* 简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们 实现成了private方法，名字保持了原来C中的。
*/
private long F(long x, long y, long z) {
return (x & y) | ((~x) & z);
}

private long G(long x, long y, long z) {
return (x & z) | (y & (~z));
}

private long H(long x, long y, long z) {
return x ^ y ^ z;
}

private long I(long x, long y, long z) {
return y ^ (x | (~z));
}

/*
* FF,GG,HH和II将调用F,G,H,I进行近一步变换 FF, GG, HH, and II transformations for
* rounds 1, 2, 3, and 4. Rotation is separate from addition to prevent
* recomputation.
*/
private long FF(long a, long b, long c, long d, long x, long s, long ac) {
a += F(b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}

private long GG(long a, long b, long c, long d, long x, long s, long ac) {
a += G(b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}

private long HH(long a, long b, long c, long d, long x, long s, long ac) {
a += H(b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}

private long II(long a, long b, long c, long d, long x, long s, long ac) {
a += I(b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}

/*
* keyBeanUpdate是keyBean的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
* 函数由getkeyBeanofStr调用，调用之前需要调用keyBeaninit，因此把它设计成private的
*/
private void keyBeanUpdate(byte[] inbuf, int inputLen) {
int i, index, partLen;
byte[] block = new byte[64];
index = (int) (count[0] >>> 3) & 0x3F;
// /* Update number of bits */
if ((count[0] += (inputLen << 3)) < (inputLen << 3))
count[1]++;
count[1] += (inputLen >>> 29);
partLen = 64 - index;
// Transform as many times as possible.
if (inputLen >= partLen) {
keyBeanMemcpy(buffer, inbuf, index, 0, partLen);
keyBeanTransform(buffer);
for (i = partLen; i + 63 < inputLen; i += 64) {
keyBeanMemcpy(block, inbuf, 0, i, 64);
keyBeanTransform(block);
}
index = 0;
} else
i = 0;
// /* Buffer remaining input */
keyBeanMemcpy(buffer, inbuf, index, i, inputLen - i);
}

/*
* keyBeanFinal整理和填写输出结果
*/
private void keyBeanFinal() {
byte[] bits = new byte[8];
int index, padLen;
// /* Save number of bits */
Encode(bits, count, 8);
// /* Pad out to 56 mod 64.
index = (int) (count[0] >>> 3) & 0x3f;
padLen = (index < 56) ? (56 - index) : (120 - index);
keyBeanUpdate(PADDING, padLen);
// /* Append length (before padding) */
keyBeanUpdate(bits, 8);
// /* Store state in digest */
Encode(digest, state, 16);
}

/*
* keyBeanMemcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
* 字节拷贝到output的outpos位置开始
*/
private void keyBeanMemcpy(byte[] output, byte[] input, int outpos,
int inpos, int len) {
int i;
for (i = 0; i < len; i++)
output[outpos + i] = input[inpos + i];
}

/*
* keyBeanTransform是keyBean核心变换程序，有keyBeanUpdate调用，block是分块的原始字节
*/
private void keyBeanTransform(byte block[]) {
long a = state[0], b = state[1], c = state[2], d = state[3];
long[] x = new long[16];
Decode(x, block, 64);
/* Round 1 */
a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */
/* Round 2 */
a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */
/* Round 3 */
a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */
/* Round 4 */
a = II(a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
d = II(d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
c = II(c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}

/*
* Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的， 只拆低32bit，以适应原始C实现的用途
*/
private void Encode(byte[] output, long[] input, int len) {
int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (byte) (input[i] & 0xffL);
output[j + 1] = (byte) ((input[i] >>> 8) & 0xffL);
output[j + 2] = (byte) ((input[i] >>> 16) & 0xffL);
output[j + 3] = (byte) ((input[i] >>> 24) & 0xffL);
}
}

/*
* Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
* 只合成低32bit，高32bit清零，以适应原始C实现的用途
*/
private void Decode(long[] output, byte[] input, int len) {
int i, j;

for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = b2iu(input[j]) | (b2iu(input[j + 1]) << 8)
| (b2iu(input[j + 2]) << 16) | (b2iu(input[j + 3]) << 24);
return;
}

/*
* b2iu是我写的一个把byte按照不考虑正负号的原则的”升位”程序，因为java没有unsigned运算
*/
public static long b2iu(byte b) {
return b < 0 ? b & 0x7F + 128 : b;
}

/*
* byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
* 因为java中的byte的toString无法实现这一点，我们又没有C语言中的 sprintf(outbuf,"%02X",ib)
*/
public static String byteHEX(byte ib) {
char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A',
'B', 'C', 'D', 'E', 'F' };
char[] ob = new char[2];
ob[0] = Digit[(ib >>> 4) & 0X0F];
ob[1] = Digit[ib & 0X0F];
String s = new String(ob);
return s;
}

public static void main(String args[]) {

keyBean m = new keyBean();
if (Array.getLength(args) == 0) { // 如果没有参数，执行标准的Test Suite
System.out.println("keyBean Test suite:");
System.out.println("keyBean(\"):" + m.getkeyBeanofStr(""));
System.out.println("keyBean(\"a\"):" + m.getkeyBeanofStr("a"));
System.out.println("keyBean(\"abc\"):" + m.getkeyBeanofStr("abc"));
System.out.println("keyBean(\"message digest\"):"
+ m.getkeyBeanofStr("message digest"));
System.out.println("keyBean(\"abcdefghijklmnopqrstuvwxyz\"):"
+ m.getkeyBeanofStr("abcdefghijklmnopqrstuvwxyz"));
System.out
.println("keyBean(\"\"):"
+ m
.getkeyBeanofStr(""));
} else
System.out.println("keyBean(" + args[0] + ")="
+ m.getkeyBeanofStr(args[0]));

}
}

F. js组合算法代码转成java代码

不必转换，我早已熟透组合排列算法：java如下


importjava.util.Arrays;
importjava.util.LinkedList;

publicclassGuy
{
	publicstaticvoidrecursionSub(LinkedList<int[]>list,intcount,int[]array,intind,intstart,int...indexs)
	{
		start++;
		if(start>count-1)
		{
			return;
		}
		if(start==0)
		{
			indexs=newint[array.length];
		}
		for(indexs[start]=ind;indexs[start]<array.length;indexs[start]++)
		{
			recursionSub(list,count,array,indexs[start]+1,start,indexs);
			if(start==count-1)
			{
				int[]temp=newint[count];
				for(inti=count-1;i>=0;i--)
				{
					temp[start-i]=array[indexs[start-i]];
				}
				list.add(temp);
			}
		}
	}

	publicstaticvoidmain(String[]args)
	{
		int[]array={1,2,3,4,5,6,7,8,9};
		LinkedList<int[]>list=newLinkedList<int[]>();
		recursionSub(list,3,array,0,-1);
		for(int[]strings:list)
		{
			System.out.println(Arrays.toString(strings));
		}
	}
}

G. JAVA 编程，算法，详细在图里， 求代码、详细解答

(a)It is insert sort algorithm of the above code segment.上面的代码是插入排序算法

(b)

EXAMPLE

AEXMPLE

AEMXPLE

AEMPXLE

AELMPXE

AEELMPX

(c)

Require 6 sorting steps.

补充完整的插入排序算法的Java程序如下

public class A{

public static void main(String[] args){

char[] a={'E','X','A','M','P','L','E'};

char v;

int i,j,n=a.length,count=0;

for (i =1; i < n; i++){

v = a[i];

j = i;

while(j > 0 && a[j-1] > v) {

a[j] = a[j-1];

j--;

}

a[j] = v;

count++;

System.out.println(new String(a));

}

System.out.println("Require "+count+" sorting steps.");

}

}

H. A*算法java实现

首先，你要知道走迷宫的思路：就是遇到岔路都往一个方向，比如往右，遇到死路就回头，回头遇到岔路继续往右。
线法线在同一平面上，反射光线与入射光线分

I. 你好 我也是做毕设 用JAVA实现APRIORI算法 能把代码发我看看吗

package com.apriori;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class Apriori {

private final static int SUPPORT = 2; // 支持度阈值
private final static double CONFIDENCE = 0.7; // 置信度阈值

private final static String ITEM_SPLIT=";"; // 项之间的分隔符
private final static String CON="->"; // 项之间的分隔符

private final static List<String> transList=new ArrayList<String>(); //所有交易

static{//初始化交易记录
transList.add("1;2;5;");
transList.add("2;4;");
transList.add("2;3;");
transList.add("1;2;4;");
transList.add("1;3;");
transList.add("2;3;");
transList.add("1;3;");
transList.add("1;2;3;5;");
transList.add("1;2;3;");
}

public Map<String,Integer> getFC(){
Map<String,Integer> frequentCollectionMap=new HashMap<String,Integer>();//所有的频繁集

frequentCollectionMap.putAll(getItem1FC());

Map<String,Integer> itemkFcMap=new HashMap<String,Integer>();
itemkFcMap.putAll(getItem1FC());
while(itemkFcMap!=null&&itemkFcMap.size()!=0){
Map<String,Integer> candidateCollection=getCandidateCollection(itemkFcMap);
Set<String> ccKeySet=candidateCollection.keySet();

//对候选集项进行累加计数
for(String trans:transList){
for(String candidate:ccKeySet){
boolean flag=true;// 用来判断交易中是否出现该候选项，如果出现，计数加1
String[] candidateItems=candidate.split(ITEM_SPLIT);
for(String candidateItem:candidateItems){
if(trans.indexOf(candidateItem+ITEM_SPLIT)==-1){
flag=false;
break;
}
}
if(flag){
Integer count=candidateCollection.get(candidate);
candidateCollection.put(candidate, count+1);
}
}
}

//从候选集中找到符合支持度的频繁集项
itemkFcMap.clear();
for(String candidate:ccKeySet){
Integer count=candidateCollection.get(candidate);
if(count>=SUPPORT){
itemkFcMap.put(candidate, count);
}
}

//合并所有频繁集
frequentCollectionMap.putAll(itemkFcMap);

}

return frequentCollectionMap;
}

private Map<String,Integer> getCandidateCollection(Map<String,Integer> itemkFcMap){
Map<String,Integer> candidateCollection=new HashMap<String,Integer>();
Set<String> itemkSet1=itemkFcMap.keySet();
Set<String> itemkSet2=itemkFcMap.keySet();

for(String itemk1:itemkSet1){
for(String itemk2:itemkSet2){
//进行连接
String[] tmp1=itemk1.split(ITEM_SPLIT);
String[] tmp2=itemk2.split(ITEM_SPLIT);

String c="";
if(tmp1.length==1){
if(tmp1[0].compareTo(tmp2[0])<0){
c=tmp1[0]+ITEM_SPLIT+tmp2[0]+ITEM_SPLIT;
}
}else{
boolean flag=true;
for(int i=0;i<tmp1.length-1;i++){
if(!tmp1[i].equals(tmp2[i])){
flag=false;
break;
}
}
if(flag&&(tmp1[tmp1.length-1].compareTo(tmp2[tmp2.length-1])<0)){
c=itemk1+tmp2[tmp2.length-1]+ITEM_SPLIT;
}
}

//进行剪枝
boolean hasInfrequentSubSet = false;
if (!c.equals("")) {
String[] tmpC = c.split(ITEM_SPLIT);
for (int i = 0; i < tmpC.length; i++) {
String subC = "";
for (int j = 0; j < tmpC.length; j++) {
if (i != j) {
subC = subC+tmpC[j]+ITEM_SPLIT;
}
}
if (itemkFcMap.get(subC) == null) {
hasInfrequentSubSet = true;
break;
}
}
}else{
hasInfrequentSubSet=true;
}

if(!hasInfrequentSubSet){
candidateCollection.put(c, 0);
}
}
}

return candidateCollection;
}

private Map<String,Integer> getItem1FC(){
Map<String,Integer> sItem1FcMap=new HashMap<String,Integer>();
Map<String,Integer> rItem1FcMap=new HashMap<String,Integer>();//频繁1项集

for(String trans:transList){
String[] items=trans.split(ITEM_SPLIT);
for(String item:items){
Integer count=sItem1FcMap.get(item+ITEM_SPLIT);
if(count==null){
sItem1FcMap.put(item+ITEM_SPLIT, 1);
}else{
sItem1FcMap.put(item+ITEM_SPLIT, count+1);
}
}
}

Set<String> keySet=sItem1FcMap.keySet();
for(String key:keySet){
Integer count=sItem1FcMap.get(key);
if(count>=SUPPORT){
rItem1FcMap.put(key, count);
}
}
return rItem1FcMap;
}

public Map<String,Double> getRelationRules(Map<String,Integer> frequentCollectionMap){
Map<String,Double> relationRules=new HashMap<String,Double>();
Set<String> keySet=frequentCollectionMap.keySet();
for (String key : keySet) {
double countAll=frequentCollectionMap.get(key);
String[] keyItems = key.split(ITEM_SPLIT);
if(keyItems.length>1){
List<String> source=new ArrayList<String>();
Collections.addAll(source, keyItems);
List<List<String>> result=new ArrayList<List<String>>();

buildSubSet(source,result);//获得source的所有非空子集

for(List<String> itemList:result){
if(itemList.size()<source.size()){//只处理真子集
List<String> otherList=new ArrayList<String>();
for(String sourceItem:source){
if(!itemList.contains(sourceItem)){
otherList.add(sourceItem);
}
}
String reasonStr="";//前置
String resultStr="";//结果
for(String item:itemList){
reasonStr=reasonStr+item+ITEM_SPLIT;
}
for(String item:otherList){
resultStr=resultStr+item+ITEM_SPLIT;
}

double countReason=frequentCollectionMap.get(reasonStr);
double itemConfidence=countAll/countReason;//计算置信度
if(itemConfidence>=CONFIDENCE){
String rule=reasonStr+CON+resultStr;
relationRules.put(rule, itemConfidence);
}
}
}
}
}

return relationRules;
}

private void buildSubSet(List<String> sourceSet, List<List<String>> result) {
// 仅有一个元素时，递归终止。此时非空子集仅为其自身，所以直接添加到result中
if (sourceSet.size() == 1) {
List<String> set = new ArrayList<String>();
set.add(sourceSet.get(0));
result.add(set);
} else if (sourceSet.size() > 1) {
// 当有n个元素时，递归求出前n-1个子集，在于result中
资料来自于http://blog.csdn.net/zjd950131/article/details/8071414 没有摘抄完