我搜索过，根本无法找到问题的答案。 我必须创建一个乐透类型模拟，6个数字+奖励数字，没有重复。 我已经设法让它工作了但是在6号阵列中，poistion [1]的数字一直都是0。我很确定它的问题很简单，但我对此很陌生，所以任何帮助都会被感激地接受。下面的代码，我确定它到处都是........
import java.util.Arrays;
public class Lotto {
public static void main(String[] args) {
int[] Lotto=new int[6];
final int MIN = 1;
final int MAX = 45;
for (int i = 0; i< Lotto.length; ++i)
{
Lotto [0] =MIN+ (int)(Math.random()*((MAX -MIN)+1));
while (Lotto[1] == Lotto[0])
{
Lotto[1] =MIN+ (int)(Math.random()*((MAX -MIN)+1));
}
while ((Lotto[2] == Lotto[0]) || (Lotto[2] == Lotto[1]) )
{
Lotto[2] = MIN+ (int)(Math.random()*((MAX -MIN)+1));
while ((Lotto[3] == Lotto[0]) || (Lotto[3] == Lotto[1]) || (Lotto[3] == Lotto[2]) )
{
Lotto[3] = MIN+ (int)(Math.random()*((MAX -MIN)+1));
}
while ((Lotto[4] == Lotto[0]) || (Lotto[4] == Lotto[1]) || (Lotto[4] == Lotto[2]) || (Lotto[4] == Lotto[3]) )
{
Lotto[4] = MIN+ (int)(Math.random()*((MAX -MIN)+1));
while ((Lotto[5] == Lotto[0]) || (Lotto[5] == Lotto[1]) || (Lotto[5] == Lotto[2]) || (Lotto[5] == Lotto[3])|| (Lotto[5] == Lotto[4]))
{
Lotto[5] = MIN+ (int)(Math.random()*((MAX -MIN)+1));
}
int[] BonusNumber=new int[1];
for (int j = 0; j< BonusNumber.length; ++j)
{
BonusNumber [j] =1+ (int)(Math.random()*((45 -1)+1));
}
System.out.println("Winner " + Arrays.toString(Lotto));
System.out.println("Bonus Number" +Arrays.toString(BonusNumber));
{
}
}
}
}
}
}
答案 0 :(得分：5)
更改此循环：
while (Lotto[1] == Lotto[0])
{
Lotto[1] = random(MIN, MAX);
}
成：
do {
Lotto[1] = random(MIN, MAX);
} while (Lotto[1] == Lotto[0]);
其余的代码相应。你看到问题所在吗？
但在开始重写相当复杂且不可维护的代码之前，请查看此实现，这更容易理解并且......更正：
final int MIN = 1;
final int MAX = 45;
final List<Integer> allPossible = new ArrayList<Integer>(MAX - MIN + 1);
for (int i = MIN; i <= MAX; ++i) {
allPossible.add(i);
}
Collections.shuffle(allPossible);
final List<Integer> lotto = allPossible.subList(0, 6);
int bonusNumber = allPossible.get(6);
System.out.println("Winner " + lotto);
System.out.println("Bonus Number" + bonusNumber);
Collections.shuffle()在这里至关重要。
答案 1 :(得分：3)
我认为您的代码非常混乱，您可以通过使用某些API实用程序来避免这么多条件，例如Collections.shuffle()，如下例所示：
public static void main(String[] args)
{
Integer[] numbers = new Integer[45];
// Populating numbers.
for (int i = 0; i < 45; i++)
numbers[i] = i + 1;
// Shuffling them to make them in random order.
List<Integer> list = Arrays.asList(numbers);
Collections.shuffle(list);
// Print any 6 of them. I chose first 6 ones for simplicity.
for (int i = 0; i < 6; i++)
System.out.print(list.get(i) + " ");
}
示例输出：
15 11 31 2 5 38
答案 2 :(得分：2)
您可以使用既不保留订单也不保留重复的HashSet。
每次需要一个新的随机数时，你也可以创建java.util.Random类的新实例，因为这会更改种子并使你的应用程序更具随机性，每次都消除包含0的位置1。
new java.util.Random().nextInt(int max)
答案 3 :(得分：1)
如果你想使用int []而不是内置类，你可以使用
int[] ints = new int[45];
for (int i = 0; i < ints.length; i++) ints[i] = i + 1;
Random rand = new Random();
for (int i = 0; i < 6; i++) {
int swap = rand.nextInt(ints.length - i) + i;
int tmp = ints[i];
ints[i] = ints[swap];
ints[swap] = tmp;
}
int[] drawn = Arrays.copyOf(ints, 6);
System.out.println(Arrays.toString(drawn));
打印
[19, 22, 24, 6, 34, 23]
答案 4 :(得分：0)
我认为我正在和你一样参加同一个简介Java课程（因为那个程序看起来非常熟悉）所以我会尝试将它保持为基本的东西;然而，我确实从您的程序中复制了所有原始代码，因此您基本上完成了所有工作，我只是稍微清理了一下。
这是完整的程序（随机化一组数字（检查重复），允许用户选择一组或随机化自己（也检查重复），对两组进行排序和比较，通知用户他们是否是否赢了，请再次参加比赛：
import java.util.*;
public class Lotto
{
public static void main(String[] args)
{
Scanner keyboard = new Scanner(System.in);
Random rand = new Random();
boolean checkPlay = false, readInput = false;
final int MAX = 45;
while (readInput != true)
{
System.out.print("Would you like to buy a lotto ticket? [y/n] ");
String stBuyTicket = keyboard.nextLine().trim().toLowerCase();
if (stBuyTicket.isEmpty())
{
System.out.println("Invalid Input.");
}
else if (stBuyTicket.charAt(0) == 'y' || stBuyTicket.charAt(0) == 'n')
{
if (stBuyTicket.charAt(0) == 'y')
{
checkPlay = true;
}
else
{
checkPlay = false;
}
readInput = true;
}
else
{
System.out.println("Invalid Input.");
}
}
while (checkPlay == true)
{
int[] lotto = new int[6];
int lottoLength = lotto.length;
int[] userLotto = new int[6];
int userLottoLength = userLotto.length;
for (int i = 0; i < lottoLength; i++)
{
boolean checkLotto = false;
while (checkLotto != true)
{
int numCheck = (rand.nextInt(MAX) + 1);
boolean confirmSame = false;
for (int j = 0; j <= i; j++)
{
if (numCheck == lotto[j])
{
confirmSame = true;
}
}
if (confirmSame != true)
{
lotto[i] = numCheck;
checkLotto = true;
}
}
}
readInput = false;
while (readInput != true)
{
System.out.println("Would you like choose your own numbers or just randomize them?");
System.out.print("Choose your own numbers? [y/n] ");
String stBuyTicket = keyboard.nextLine().trim().toLowerCase();
if (stBuyTicket.isEmpty())
{
System.out.println("Invalid Input.");
}
else if (stBuyTicket.charAt(0) == 'y' || stBuyTicket.charAt(0) == 'n')
{
if (stBuyTicket.charAt(0) == 'y')
{
for (int i = 0; i < userLottoLength; i++)
{
boolean checkUserLotto = false;
while (checkUserLotto != true)
{
System.out.print("Which number would you like to choose for number " + (i + 1) + ": ");
String numUserInput = keyboard.nextLine().trim();
int numUserInputLength = numUserInput.length();
boolean checkInput = true;
if (numUserInputLength > 2 || numUserInputLength < 1)
{
System.out.println("Invalid Input. Try again.");
checkInput = false;
}
else
{
for (int j = 0; j < numUserInputLength; j++)
{
if (Character.isDigit(numUserInput.charAt(j)) != true)
{
System.out.println("Invalid Input. Try again.");
checkInput = false;
}
}
}
if (checkInput == true)
{
int userInput = Integer.parseInt(numUserInput);
if (userInput > MAX || userInput < 1)
{
System.out.println("Invalid Input. Try again.");
}
else
{
boolean confirmSame = false;
for (int j = 0; j <= i; j++)
{
if (userInput == userLotto[j])
{
System.out.println("You've already choosen this number. Choose again.");
confirmSame = true;
}
}
if (confirmSame != true)
{
userLotto[i] = userInput;
checkUserLotto = true;
}
}
}
}
}
}
else
{
for (int i = 0; i < userLottoLength; i++)
{
boolean checkLotto = false;
while (checkLotto != true)
{
int numCheck = (rand.nextInt(MAX) + 1);
boolean confirmSame = false;
for (int j = 0; j <= i; j++)
{
if (numCheck == userLotto[j])
{
confirmSame = true;
}
}
if (confirmSame != true)
{
userLotto[i] = numCheck;
checkLotto = true;
}
}
}
}
readInput = true;
System.out.print("Your lotto numbers are: " + userLotto[0]);
for (int i = 1; i < userLottoLength; i++)
{
System.out.print(", " + userLotto[i]);
}
System.out.print("!");
System.out.println();
System.out.print("And the winning lotto numbers are: " + lotto[0]);
for (int i = 1; i < lottoLength; i++)
{
System.out.print(", " + lotto[i]);
}
System.out.print("!");
System.out.println();
Arrays.sort(lotto);
Arrays.sort(userLotto);
if (Arrays.equals(userLotto, lotto) == true)
{
System.out.println("Your lotto numbers match the winning lotto numbers! \nYou win!");
}
else
{
System.out.println("Your lotto numbers do not match the winning lotto numbers. \nYou lose.");
}
}
else
{
System.out.println("Invalid Input.");
}
}
readInput = false;
while (readInput != true)
{
System.out.print("Would you like to buy another lotto ticket? [y/n] ");
String stBuyTicket = keyboard.nextLine().trim().toLowerCase();
if (stBuyTicket.isEmpty())
{
System.out.println("Invalid Input.");
}
else if (stBuyTicket.charAt(0) == 'y' || stBuyTicket.charAt(0) == 'n')
{
if (stBuyTicket.charAt(0) == 'y')
{
checkPlay = true;
}
else
{
checkPlay = false;
}
readInput = true;
}
else
{
System.out.println("Invalid Input.");
}
}
}
System.out.println("That's a good decision. Save your money");
System.exit(0);
}
}
以下是没有重复的随机化乐透集的部分：
for (int i = 0; i < lottoLength; i++) {
boolean checkLotto = false;
while (checkLotto != true) {
int numCheck = (rand.nextInt(MAX) + 1);
boolean confirmSame = false;
for (int j = 0; j <= i; j++) {
if (numCheck == lotto[j]) {
confirmSame = true;
}
}
if (confirmSame != true) {
lotto[i] = numCheck;
checkLotto = true;
}
}
}
它生成一个带int numCheck = (rand.nextInt(MAX) + 1)的数字，并检查该数字是否与目前为止输入的每个乐透号码相对应：
for (int j = 0; j <= i; j++) {
if (numCheck == lotto[j]) {
confirmSame = true;
}
}
如果numCheck不等于任何输入的数字，则numCheck将写入当前阵列点。