Question

目前卡在我的乐透计划中的一个错误，例如;如果我输入1,2,3,4,5并再次输入5，我收到警告我有5个副本，但如果我再次输入，我没有收到警告，我可以输入任何我想要的号码，它会打印出来。

    package lottery;


import java.util.*;

public class Lottery {
    public static final int NUMBERS = 6;//controlls the min and max numbers needed for the lotto
    public static final int MIN_NUMBER = 1;
    public static final int MAX_NUMBER = 42;


    public static void main(String[] args) {
        // get winning number and ticket sets
        Set<Integer> winningNumbers = createWinningNumbers();
        Set<Integer> ticket = getTicket();
        System.out.println();

        // Display and keeps only the winning numbers from the user's ticket
        Set<Integer> intersection = new TreeSet<>(ticket);
        intersection.retainAll(winningNumbers);

        // print out the results by fetching input from the user and randomly generated numbers.
        System.out.println("Your ticket numbers are " + ticket);
        System.out.println("The winning numbers are " + 
                           winningNumbers);
        System.out.println();
        System.out.println("You had " + intersection.size() + 
                           " matching numbers.");
        if (intersection.size() > 0) {
            double prize = 100 * Math.pow(2, intersection.size());
            System.out.println("The matched numbers are " + 
                               intersection);
            System.out.println("Your prize is $" + prize);
        }

    }

    // generates a set of the winning lotto numbers
    public static Set<Integer> createWinningNumbers() {
        Set<Integer> winningNumbers = new TreeSet<>();
        Random r = new Random();
        while (winningNumbers.size() < NUMBERS) {
            int number = r.nextInt(MAX_NUMBER) + 1;
            winningNumbers.add(number);
        }
        return winningNumbers;
    }

    // reads the player's lottery ticket from the console
    public static Set<Integer> getTicket() {
        Set<Integer> ticket = new TreeSet<>();
        Scanner console = new Scanner(System.in);
        Scanner input = new Scanner(System.in);
        System.out.print("Type in your " + NUMBERS + //prints out asking for you to type in your numbers
                         " unique lotto numbers: ");

            int inputSize = 0;
        while (input.hasNextInt() && inputSize <NUMBERS) {
            int getTicket = input.nextInt();
            if (getTicket< MIN_NUMBER || getTicket > MAX_NUMBER) {//prints out if number is not within the lotto range
                System.out.println("Your number must be in " + MIN_NUMBER + " - " + MAX_NUMBER + " range.");
        }
        else {

        if (ticket.add(getTicket)) {//prints out if number successfully added
                 System.out.println("Number added successfully");
        }       
        else {// prints out if number is not successfully added.
                 System.out.println("Duplicate number detected");
        }
            inputSize++;
        }

        }
        while (ticket.size() < NUMBERS) {
            int number = console.nextInt();
            ticket.add(number);
        }

        return ticket;


    }//close main() function  
}//close Lottery class

Answer 1

更改getTicket()

内的while循环

// reads the player's lottery ticket from the console
public static Set<Integer> getTicket()
{
    Set<Integer> ticket = new TreeSet<>();
    Scanner input = new Scanner(System.in);
    System.out.println("Please enter " + NUMBERS + " unique lotto numbers!");

    int validInputs = 0;
    while (input.hasNextInt() && validInputs < NUMBERS)
    {
        System.out.printf("Enter number %d: ", validInputs);
        int getTicket = input.nextInt();
        if (getTicket< MIN_NUMBER || getTicket > MAX_NUMBER)
        {
            //prints out if number is not within the lotto range
            System.out.println("Your number must be in " +
                MIN_NUMBER + " - " + MAX_NUMBER + " range.");
        }
        else
        {
            if (ticket.add(getTicket))
            {
                //prints out if number successfully added
                System.out.println("Number added successfully");
                validInputs++; // Increment valid inputs here
            }       
            else
            {
                // prints out if number is not successfully added.
                System.out.println("Duplicate number detected");
            }
        }
    }
}

为什么你在一个功能中使用两个扫描仪？

Scanner console = new Scanner(System.in);
Scanner input = new Scanner(System.in);

Answer 2

您的代码不需要第二个while循环

 while (ticket.size() < NUMBERS) {
        int number = console.nextInt();
        ticket.add(number);
    }

因为它不包含上面实现的逻辑。

只需删除它，只有在将有效数字添加到集合时才会增加inputSize（例如，当您打印出“成功消息”时）。然后第一个循环将运行，直到用户输入6个有效（唯一）数字

乐透程序的范围和重复错误

2 个答案: