A lottery game in Java

A lottery game in Java

This is an assignment for class that I am working on. I am not looking for
answers, just a bit of guidance. I am stuck in a few places and have a
feeling that I am really lacking. Anything at all is appreciated.
A simulation of a lottery drawing. Player picks a set of numbers. A random
drawing of numbers is then made, and the player wins if his/her chosen
numbers match the drawn numbers (disregarding the order of the numbers).
A player picks k distinct numbers between 1 and n (inclusive), as well as
one bonus number between 1 and m (inclusive). "Distinct" means that none
of the first k numbers may be repeated. However, the bonus number may or
may not coincide with one of the k distinct numbers. The distinct numbers
as well as the bonus number must match the drawn values for the player to
win the jackpot.
For example, in the TN Lottery's Powerball game, a player picks five
numbers between 1 and 59, inclusive, and one "Powerball number" between 1
and 35, inclusive. Here, the number of possible lottery tickets is:
(59*58*57*56*55 / 5*4*3*2*1) * 35 = 175,223,510
A single ticket's chance of winning the jackpot is then 1/175,223,510,
which is about 0.0000000057.
Allow the user to enter values for k, n, and m above. Then, ask the user
to enter the numbers that s/he wishes to play (this is your program's
equivalent of "buying" a lottery ticket). Store the k distinct numbers
into an array, but keep the bonus number separate.
The program should compute and display the probability of winning the
jackpot for the selected game. Then, it should randomly "draw" the winning
numbers and determine if the user-entered numbers match. Keep in mind that
the matching for the k distinct values should disregard the order of the
numbers. The winning numbers should be shown, along with an appropriate
message indicating whether or not the user won the jackpot. Allow the user
to play as many games as s/he wants.
Error Checking Implement error checking on all user inputs, to the extent
we've discussed it in class (don't worry about data type mismatches).
Error checking should repeatedly prompt for the input until the user
enters a valid value. For example, the user should not be able to enter
negative inputs. The user input should also be checked to see that it
matches the entered values for n and m – for example, in a game where n =
59, the user should not be able to pick 60 for his/her ticket. Also make
sure that you're checking for distinct inputs when the player chooses
numbers – a player shouldn't be able to pick the same number more than
once (with the exception of the bonus number).
Code Organization Your program should use methods to break the code down
into manageable chunks. At minimum, include the following methods
(although you are welcome to add more if you want).
// Returns the probability of winning the jackpot in a lottery drawing
with the
// specified parameters.
public static double jackpotChance(int k, int n, int m)
// Allows the user to enter k distinct integers between 1 and n. Must include
// error checking to ensure that each entered number is within the valid
range and // does not coincide with any previously entered number.
Returns an array of
// the entered numbers.
public static int[] enterNumbers(int k, int n)
// Draws k distinct random integers between 1 and n. Returns an array of
the drawn // numbers.
public static int[] drawNumbers(int k, int n)
// Returns whether the two arrays a and b contain the same elements,
without //regardtoorder. Forexample,ifa={1,4,3,2}andb={1,2,3,4}, //
this method should return true.
public static boolean containSameElements(int[] a, int[] b)
import java.util.*;
public class Lottery {
//Returns the probability of winning the jackpot in a lottery drawing with
the
//specified parameters.
//STILL NEEDED: ALL
public static double jackpotChance(int k, int n, int m)
{
double jackpotChance = 0;
return jackpotChance;
}
//Allows the user to enter k distinct integers between 1 and n. Must include
//error checking to ensure that each entered number is within the valid
range and
//does not coincide with any previously entered number. Returns an array of
//the entered numbers.
//STILL NEEDED: ERROR CHECKING TO ENSURE USERPICK IS A DISTINCT NUMBER
public static int[] enterNumbers(int k, int n)
{
System.out.println();
Scanner input = new Scanner(System.in);
//asks for user input, takes user input for variables k & n
System.out.println("Enter k.");
k = input.nextInt();
System.out.println("Enter n.");
n = input.nextInt();
final int SIZE = k; //stores k into final variable SIZE
int enterNumbers[]= new int[SIZE]; //declares enterNumbers array
int userPick;
System.out.println("Enter " + k + " distinct integers between 1 and "
+ n + ".");
int i=SIZE;
for (i = 0; i < enterNumbers.length; i++) {
System.out.println("Enter the next number to store:");
userPick = input.nextInt();
if (userPick >= 1 && userPick <= n) {
enterNumbers[i] = userPick;
} else {
System.out.println("Invalid input, please try again.");
i--;
}
}
System.out.println();
System.out.println("Your chosen numbers are: ");
for (i = 0; i < enterNumbers.length; i++) {
System.out.print(enterNumbers[i] + " ");
}
System.out.println();
System.out.println("Enter m.");
int m = input.nextInt();
jackpotChance(k,n,m);
drawNumbers(k,n);
return enterNumbers;
}
//Draws k distinct random integers between 1 and n. Returns an array of
the drawn
// numbers.
//STILL NEEDED: ERROR CHECKING TO ENSURE RANDOMNUMBER IS A DISTINCT NUMBER
public static int[] drawNumbers(int k, int n)
{
int drawNumbers[]= new int[k]; //declares enterNumbers array
int randomNumber;
int i=k;
for (i = 0; i < drawNumbers.length; i++) {
randomNumber = (int) (Math.random()*n + 1);
drawNumbers[i] = randomNumber;
}
System.out.println();
System.out.println("Your drawn numbers are: ");
for (i = 0; i < drawNumbers.length; i++) {
System.out.print(drawNumbers[i] + " ");
}
return drawNumbers;
}
//Returns whether the two arrays a and b contain the same elements, without
//regardtoorder. Forexample,ifa={1,4,3,2}andb={1,2,3,4},
//this method should return true.
//STILL NEEDED: ALL
public static boolean containSameElements(int[] enterNumbers, int[]
drawNumbers)
{
}
public static void main (String[] args)
{
System.out.println("Welcome to THE LOTTERY GAME!");
System.out.println("----------------------------");
int k = 0;
int n = 0;
enterNumbers(k,n);
}
}