简单的爬山算法?

时间:2011-03-15 05:36:29

标签: java algorithm artificial-intelligence traveling-salesman hill-climbing

我正在尝试使用简单的爬山算法来解决旅行商问题。我想创建一个Java程序来执行此操作。我知道这不是最好用的,但我主要希望它能看到结果,然后将结果与我将创建的以下内容进行比较:

  • 随机山登山者
  • 随机重启希尔登山者
  • 模拟退火。

无论如何回到简单的爬山算法我已经有了这个:

import java.util.*;
public class HCSA 
{
    static private Random rand; 
    static public void main(String args[])
    {
        for(int i=0;i<10;++i) System.out.println(UR(3,4));
    }
    static public double UR(double a,double b)
    {
        if (rand == null) 
        {
            rand = new Random();
            rand.setSeed(System.nanoTime());
        }
        return((b-a)*rand.nextDouble()+a);
    }
}

这就是我需要的吗?这个代码是否正确..?我在文本文档中有一系列不同的数据集,我希望程序从中读取然后生成结果。

真的很感激任何帮助。

-----编辑----

我是一个白痴,直接打开Eclipse文件,我应该先在记事本中打开它。这是我现在的代码。

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.Reader;
import java.io.StreamTokenizer;
import java.util.ArrayList;

{
    //Print a 2D double array to the console Window
    static public void PrintArray(double x[][])
    {
        for(int i=0;i<x.length;++i)
        {
            for(int j=0;j<x[i].length;++j)
            {
                System.out.print(x[i][j]);
                System.out.print(" ");
            }
            System.out.println();
        }
    }
    //reads in a text file and parses all of the numbers in it
    //is for reading in a square 2D numeric array from a text file
    //This code is not very good and can be improved!
    //But it should work!!!
    //'sep' is the separator between columns
    static public double[][] ReadArrayFile(String filename,String sep)
    {
        double res[][] = null;
        try
        {
            BufferedReader input = null;
            input = new BufferedReader(new FileReader(filename));
            String line = null;
            int ncol = 0;
            int nrow = 0;

            while ((line = input.readLine()) != null) 
            {
                ++nrow;
                String[] columns = line.split(sep);
                ncol = Math.max(ncol,columns.length);
            }
            res = new double[nrow][ncol];
            input = new BufferedReader(new FileReader(filename));
            int i=0,j=0;
            while ((line = input.readLine()) != null) 
            {

                String[] columns = line.split(sep);
                for(j=0;j<columns.length;++j)
                {
                    res[i][j] = Double.parseDouble(columns[j]);
                }
                ++i;
            }
        }
        catch(Exception E)
        {
            System.out.println("+++ReadArrayFile: "+E.getMessage());
        }
        return(res);
    }
    //This method reads in a text file and parses all of the numbers in it
    //This code is not very good and can be improved!
    //But it should work!!!
    //It takes in as input a string filename and returns an array list of Integers
    static public ArrayList<Integer> ReadIntegerFile(String filename)
    {
        ArrayList<Integer> res = new ArrayList<Integer>();
        Reader r;
        try
        {
            r = new BufferedReader(new FileReader(filename));
            StreamTokenizer stok = new StreamTokenizer(r);
            stok.parseNumbers();
            stok.nextToken();
            while (stok.ttype != StreamTokenizer.TT_EOF) 
            {
                if (stok.ttype == StreamTokenizer.TT_NUMBER)
                {
                    res.add((int)(stok.nval));
                }
                stok.nextToken();
            }
        }
        catch(Exception E)
        {
            System.out.println("+++ReadIntegerFile: "+E.getMessage());
        }
        return(res);
    }
}

2 个答案:

答案 0 :(得分:3)

您可以将结果与教科书的代码存储库进行比较 “Artificial Intelligence a Modern Approach”,这是aima code repository 他们的爬山实施是HillClimbingSearch.java

答案 1 :(得分:2)

我不确定您粘贴的代码与旅行推销员有什么关系。您有一个函数UR,它在[a,b)区间内生成一个随机数。