[jspak]

Hi I'm trying to write a program where it generates 20 numbers in between 1-50 then it displays the frequency of the numbers after it. I have it where it displays the random numbers and I have the code for the frequency part written. The only problem I'm having is the 20 random numbers aren't being stored into an array. I know this because when it displays the frequency it comes up all zeros. Here's the code.

import java.util.*;
import java.io.*;
public class Project6 
{
	
	public static void main(String[] args)
	{
		ObjectOutputStream outputStream=null;
		ObjectInputStream inputStream=null;
		Random generator= new Random();
		Random[] y= new Random [20];
		try
		{
			outputStream= new ObjectOutputStream(new FileOutputStream("numbers.dat"));
			inputStream= new ObjectInputStream(new FileInputStream("numbers.dat"));
			
			int number;
                        
			int i; 
			int [] x= new int[20];
                        
                        
			int r= generator.nextInt(51);
                     
			
			
			for(i=1; i<=x.length;i++)
			{	
				outputStream.writeInt(generator.nextInt(51));
			}
			
			
			
			
			System.out.println("Numbers written to the file numbers.dat.");
			outputStream.close();
			
			try
			{
				while(true)
				{
					number=inputStream.readInt();
					//read 'number' into array 'x' here
					
					System.out.println(number);
					
				}
			}
			
			catch(EOFException e)
			{
				System.out.println("No more numbers in file");
				
					
			}
			//this loop should count frequency of how many times a number occur in array 'x'
			int count=0;
			for(i=0;i<x.length;i++)
			{ count=1;
				for(int j=0; j<x.length;j++)
				{
					if(x[i]== x[j]){
					count++;}
				}
			System.out.println(x[i]);	
				
			}
			
			
				
		}
		
		
		catch(IOException e)
		{
			System.out.println("Problem with file output");
			
		}
		
		
		
			
	}
	
	
	
	

}

[g00se]

There's a bit of confusion here. Only one Random class is needed. The main part would be

final int HOW_MANY = 20;
int[] x = new int[HOW_MANY];
Random n = new Random();
for(int i = 0;i < HOW_MANY;i++) {	
  x[i] = 1 + n.nextInt(49);
}
// Now serialize

This post has been edited by g00se: 21 March 2012 - 02:30 PM

[jspak]

Okay I got it to store the numbers into the array. Now I'm having trouble with the frequency count. I guess the code I wrote for the frequency count just displays my array?
Here's what I have.

import java.util.*;
import java.io.*;
public class Project6 
{
	
	public static void main(String[] args)
	{
		ObjectOutputStream outputStream=null;
		ObjectInputStream inputStream=null;
		Random generator= new Random();
		
                
                
                
		try
		{
			outputStream= new ObjectOutputStream(new FileOutputStream("numbers.dat"));
			inputStream= new ObjectInputStream(new FileInputStream("numbers.dat"));
			
			int number;
                        
			int i; 
			int [] x= new int[20];
                        
                        
			int r= generator.nextInt(51);
                     
			for(i=0;i<x.length;i++)
                        {
                            x[i]=generator.nextInt(51);
                        }
			
			for(i=1; i<=x.length;i++)
			{	
				outputStream.writeInt(generator.nextInt(51));
			}
			
			
			
			
			System.out.println("Numbers written to the file numbers.dat.");
			outputStream.close();

			int count=0;
			for(i=0;i<x.length;i++)
			{ count=1;
				for(int j=0; j<x.length;j++)
				{
					if(x[i]== x[j]){
					count++;}
				}
			System.out.println(x[i]);
                        
				
			}
			
			
				
		}
		
		
		catch(IOException e)
		{
			System.out.println("Problem with file output");
			
		}
		
		
		
			
	}
	
	
	
	

}

[g00se]

If you want to record frequencies, you need another array big enough (51 elements) to store your frequency range (0 to 50 inclusive)