code ninja needed

[iKillburger]

My teacher is obsessed with magic 8 balls and she asked how many times it would take to roll every answer. I wrote a reeealy simple program and for some reason it wont work. I know there are other ways to write this using more complicated number checks but this way should be fastest since java's slow as crap. Anyways I know the conditional statement works even if it seems strange. What happens though is the same random number is picked 40 times in a row. Just so u know there are 20 sides to a magic 8ball. here's the source
import java.util.Random;

public class magic
{

public static void main(String args[])
{
int trials=50; //running the program multiple times to get a better average
int results[]; //stores how many tries each trial took
results=new int[trials];
int average=0; //will become the average number of tries for all trials
for(int a=0;a<trials;a++) //runs the loop trial number of times
{
int numgotten=0; //number of times an appropriate number was rolled
int tries=0; //number of times the 8 ball has been rolled
while(numgotten!=20) //rolls the 8ball until all 20 answers have been given
{
tries++; //records that the 8ball was rolled
//System.out.println("numleft: "+(20-numgotten) + " " + " tries: "+tries); //debug helper
if(roll(20-numgotten)) //requests the roll method to be called
{
numgotten++; //records that an unused answer was rolled
//System.out.println("true"); //debug helper
}
else
{
//System.out.println("false");//debug helper
}
System.out.println(); //spacer
results[a]=tries; //stores the number of tries that were needed to roll all 20 sides
}
}
for(int b=0;b<trials;b++) //these three lines calculate the overall average of times the 8 ball was rolled
average+=results[b];
average/=(trials);

for(int b=0;b<trials;b++)
{
System.out.println(results[b]); //displays all the results from the different trials
for(int d=0;d<100000000;d++){} //the lazy programmer's delay
}
System.out.println("average of "+trials+" trials is "+average);
}
public static boolean roll(int a)
{
Random rand = new Random(); //problem is here or in next line
int numpicked=rand.nextInt(20)+1; //range is 1-20
//odds of getting new number is (20-numgotten)/20*100%
//this sees if the number rolled is 1 the answers not yet rolled
//you can imagine this as putting all the unpicked answers at the bottom and every time the answer is rolled
//that answer is moved to the top and all the unused answers are moved down

// System.out.println("random number:" +numpicked); //debug look close at this onw
if(numpicked<=a)//need to see if random number is 1 we havent gotten
return true;
else
return false;
}
}

**edit: i added in some comments but i dpnt have a compiler with me so i dont know if this compiles. The problem is that for some reason the same random number is being sent over and over many times in a row. java can be at least up to 8 times slower than c/c++ depending on what ure doing. And what's wrong with my programming?? itll be easier to read if u

[Richard Creager]

CODE tags are nice.
I fart out diamonds.

[Vitron]

CODE tags are nice............

import java.util.Random;

public class magic
{
	
	public static void main(String args[])
	{
		int trials=50;
		int results[];
		results=new int[trials];
		int average=0;
		for(int a=0;a<trials;a++)
		{
			int numgotten=0;
			int tries=0;
			while(numgotten!=20)
			{
				tries++;
			//	System.out.println("numleft: "+(20-numgotten) + "  " + "  tries: "+tries);
				if(roll(20-numgotten))
				{
					numgotten++;
				//	System.out.println("true");
				}
				else 
				{
			//		System.out.println("false");
				}	
				System.out.println();
				results[a]=tries;
			}
		}
		for(int b=0;b<trials;b++)
		average+=results[b];
		average/=(trials);
		
		for(int b=0;b<trials;b++)
		{
		System.out.println(results[b]);
		for(int d=0;d<100000000;d++){}
		}
		System.out.println("average of "+trials+" trials is "+average); 
	}
	public static boolean roll(int a)
	{
		Random rand = new Random();//problem is here or in next line
		int numpicked=rand.nextInt(20)+1;//range is 1-20
		//odds of getting new number is (20-numgotten)/20*100%
		//see if 1 of 20 numbers is less than or equal to ones we havent gotten
		
	//	System.out.println("random number:" +numpicked);
		if(numpicked<=a)//need to see if random number is 1 we havent gotten
			return true;
		else
			return false;
	}
}

[Fallen Angel]

Your code is seriously messed up.
And Java is by no means "slow as crap".

[Ikrit]

import java.util.*;

public class magic {
	
	static Random rand = new Random();
	
	public static void main(String args[]) {
		boolean found[] = new boolean[20];
		boolean all = false;
		int count = 0;
		while(!all) {
			count++;
			int thisRoll = roll();
			
			found[thisRoll] = true;
			
			if(!check(found))
				all = true;
		}
		
		System.out.println(count);
	}
	
	public static int roll() {
		return rand.nextInt(20);
	}
	
	public static boolean check(boolean found[]) {
		boolean aFalse = false;
		for(int k = 0;k < found.length;k++) {
			if(found[k] == false)
				aFalse = true;
		}
		
		return aFalse;
	}
}

I'd probly do something more like the code I posted... it's a hell of alot easier than whatever it was you posted.

[iKillburger]

well thanks 4 the help. still curious about why it errored like that tho.