Java Learning movie "Social network" Facemash algorithm implementation

Algorithmic theory Reference: http://www.biaodianfu.com/fackbook-facemash-algorithm.html

Realize:

Import java.util.List;

public class User {
private String name; User name
private double integral; Integral
private double rank; Ranking

Public User (String name,double integral,int rank) {
THIS.name = name;
This.integral = integral;
This.rank = rank;
}
Public User () {

}
/**
* Get user points ranking
* @return
*/
public int getuserranking () {
int result = 0;

return result;
}

Public String GetName () {
return name;
}
Public String getnamestring () {
return GetName ();
}

Public Double getintegral () {
return integral;
}
Public double getintegralstring ()
{
return Getintegral ();
}
public void Getnewintegral (double a) {
This.integral = A;
}

Public double GetRank () {
return rank;
}
Public double getrankstring ()
{
return GetRank ();
}
public void Getnewrank (double a) {
This.rank = A;
}

/**
* Get user name points rank
* @return
*/
Public String getuserstring ()
{
return getrankstring () + ":" +getnamestring () + "" +
"" +getintegralstring ();
}
/**
* Print user Information
* @return
*/

public static String Getoutputuser (List User)
{
String result= "";
for (int i = 0; i < user.size (); i++)
{
User item= (user) user.get (i);
Result+=item.getuserstring () + "\ r \ n";
}
return result;
}

}

Import Java.util.arraylist;import java.util.Comparator;
Import java.util.List;
Import java.util.ArrayList;
Import java.util.Collections;

public class Useritem {

public static void Main (string[] args)
{
TODO auto-generated Method Stub
Test1 ();
}

public static void Test1 ()
{
User P=new User ("Wanglei", 0.55, 1);
User P2=new User ("Yangjiang", 0.54,2);
User P3=new User ("Xuepeng", 0.53, 3);
User P4=new User ("Zhukai", 0.52,4);
User P5=new User ("Zhenshan", 0.51,5);
List list=new ArrayList ();
List.add (P);
List.add (p2);
List.add (p3);
List.add (p4);
List.add (p5);
System.out.println (User.getoutputuser (list));
Match AA = new match ();
Aa.setuser (P,P2);
Aa.setexpect ();
Aa.setscore ();
P.getnewintegral (Aa.setintegral_a ());
P2.getnewintegral (Aa.setintegral_b ());
Aa.setuser (P3,P4);
Aa.setexpect ();
Aa.setscore ();
P3.getnewintegral (Aa.setintegral_a ());
P4.getnewintegral (Aa.setintegral_b ());
Aa.setuser (P3,P5);
Aa.setexpect ();
Aa.setscore ();
P3.getnewintegral (Aa.setintegral_a ());
P5.getnewintegral (Aa.setintegral_b ());
Aa.setuser (P2,P4);
Aa.setexpect ();
Aa.setscore ();
P2.getnewintegral (Aa.setintegral_a ());
P4.getnewintegral (Aa.setintegral_b ());

System.out.println (User.getoutputuser (list));

Comparatoruser comparator=new Comparatoruser ();
Collections.sort (list, comparator);

for (int i=0;i<list.size (); i++) {
User user_temp= (user) list.get (i);
User_temp.getnewrank (List.size ()-i);
}
System.out.println (User.getoutputuser (list));
}

}

Import Java.lang.Math;

public class Match {
Private User user_a;
Private User User_b;
Private double expect_a = 0;
Private double expect_b = 0;
Private double score_a = 0;
Private double score_b = 0;
Private double score = 0;


/**
* Get the results of the game
* @return
*/
Public double Getscore ()
{
if (score = = 0)
{
Score = 1;
}
Else
{
Score = 0;
}
return score;
}


public static long Pow (double x,double y)
/**
* Get success expectations
* @return
*/
Public double getexpect_a ()
{
Double result = 0;
1/(1+10^ ((Ib-ia)/400))
result = 1/(1 + math.pow (user_b.getintegral ()-user_a.getintegral ())/400);
return result;
}
Public double Getexpect_b ()
{
Double result = 0;
1/(1+10^ ((IA-IB)/400))
result = 1/(1 + math.pow (user_a.getintegral ()-user_b.getintegral ())/400);
return result;
}

/**
* Earn points after the game
* @return
*/
Public double setintegral_a ()
{
User_a.getintegral () = user_a.getintegral () + score_a-expect_a
return user_a.getintegral () + score_a-expect_a;
}
Public double Setintegral_b ()
{
return user_b.getintegral () + score_b-expect_b;
}
public void SetUser (User a,user B)
{
This.user_a = A;
This.user_b = b;
}

public void Setexpect ()
{
This.expect_a = Getexpect_a ();
This.expect_b = Getexpect_b ();
}
public void SetScore ()
{
This.score_a = Getscore ();
This.score_b = Getscore ();
}

}

Import Java.util.Comparator;
Import java.util.List;
Import java.util.ArrayList;
Import java.util.Collections;

public class Comparatoruser implements comparator{

public int Compare (object arg0, object arg1) {
User user0= (user) arg0;
User user1= (user) arg1;
int flag = 0;
Flag = User0.getintegral (). CompareTo (User1.getintegral ());
return flag;
}
}

Learning experience:

1 Import java.util.List;

Import java.util.ArrayList;

Familiar with partial usage of list and ArrayList class, such as inserting operations;

Extension: http://blog.sina.com.cn/s/blog_68f262210100mape.html

Http://jingyan.baidu.com/article/851fbc37d844553e1f15abe1.html

2 Import Java.lang.Math;

Be familiar with the arithmetic of math class;

Extension: http://wxb-j2ee.iteye.com/blog/1010258

http://blog.csdn.net/lixiang0522/article/details/7557851

Http://www.cnblogs.com/ksuifeng/archive/2010/03/24/1693856.html

3 Import Java.util.Comparator;

Import java.util.Collections;

familiar with comparator and collections class, combine ArrayList class, realize array sort;

Extension: http://www.blogjava.net/zygcs/archive/2008/01/17/176032.html

Http://www.cnblogs.com/fzzl/archive/2010/08/14/1799408.html

http://blog.csdn.net/toweryangtao/article/details/7518325

4 Fix the problem:

Java hint cannot invoke compareTo (double) on the primitive type double

Reason:

Workaround: Set the Getintegral method of the object to double instead of double;

Public Double getintegral () {
return integral;
}

5 MyEclipse

Http://www.baidu.com/s?wd=myeclipse Font Size setting &TN=11000002_IE_DG

Java Learning movie "Social network" Facemash algorithm implementation