Simple hill climbing algorithm? [closed]
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Closed 7 years ago.
Improve this questionI'm trying to use the Simple hill climbing algorithm to solve the travelling salesman problem. I want to create a Java program to do this. I know it's not the best one to use but I mainly want it to see the results and then compare the results with the following that I will also create:
- Stochastic Hill Climber
- Random Restart Hill Climber
- Simulated Annealing.
Anyway back to the simple hill climbing algorithm I already have this:
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);
}
}
Is this all I need? Is this code even right..? I have a range of different datasets in text documents that I want the program to read from and then produce results.
Would really appreciate any help on this.
----- EDIT ----
I was being an idiot and opened the Java file straight into Eclipse when i should have opened it in notepad first.. here is the code i have now got.
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]);
开发者_如何学JAVA }
++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);
}
}
You can compare your results against the code repository for the textbook
"Artificial Intelligence a Modern Approach", here is the aima code repository.
Their hill climbing implementation is HillClimbingSearch.java
I'm not sure what the code you pasted has to do with Traveling Salesman. You have a function UR
which generates a random number in the interval [a,b)
.
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