Question

这是我的代码

import java.util.Scanner; //make use of scanner class to input values
import java.util.Random; //get random number


public class MarkSix5
{
    public static void main(String[] args)
    {
        final int SIZE_OF_MARKSIX = 7;
        final int SIZE_OF_PERIODS = 5;

        //Ask user to enter how many periods of draw results he/she wants
        Scanner input = new Scanner(System.in);

        int[] markSix = new int[SIZE_OF_MARKSIX * SIZE_OF_PERIODS];

        //Ask user to enter the past results
        for(int j=0; j<5; j++)
        {   
            int temp=0;
            String periodNumber="";
            if (j==0) periodNumber="1st";
            else if (j==1){periodNumber="2nd";temp =7;}
            else if (j==2){periodNumber="3rd";temp=14;}
            else if (j==3){periodNumber="4th";temp=21;}
            else {periodNumber="5th";temp=28;}

            System.out.print("Please enter the past results of the " + periodNumber + " MarkSix: ");

            for(int i=1*temp; i<SIZE_OF_MARKSIX+temp; i++)
            {
                markSix[i]=input.nextInt();
            }

            System.out.println("");
        }

        //generate random numbers
        Random rand = new Random();
        int[] theRandomNumber = new int[6];
        int decision=1;    
        do
        {
            //initialize the new set of numbers
            for(int k =0; k<6; k++)
            {
                theRandomNumber[k] = rand.nextInt(49)+1;
            }
            //check that the new set of numbers with conditions
            for(int a=0;a<7;a++)
            { //need to consider how many times to check
                for(int k=0;k<6;k++)
                {
                    for(int j=0; j<35;j++) //ensure no past draw numbers
                    {
                        while (theRandomNumber[k]==markSix[j])//**This is the bug**
                        {                       
                            theRandomNumber[k] = rand.nextInt(49)+1;
                        }
                    }

                    { for(int j=0; j<6;j++) //check duplicate numbers
                    {          
                        while (theRandomNumber[k]==theRandomNumber[j])//**This is the bug**
                        {
                            theRandomNumber[k] = rand.nextInt(49)+1;                
                        }
                    }
                    }
                }
            }

            //print out results
            System.out.println("A new set of numbers: " +theRandomNumber[0] + " " +theRandomNumber[1] + " "+theRandomNumber[2]+" "+ theRandomNumber[3]+ " " +theRandomNumber[4]+ " "+theRandomNumber[5]+".");
            System.out.println("Do you want to have another set of numbers?(if yes, type 0)");  
            decision = input.nextInt();

        }while (decision==0);  
    }

}

程序应首先要求用户输入5组数字。然后打印出一组在5组数字中不存在的新数字。

当我使用while循环时，我的程序在这里停止。

在我改变之后，它确实有效。但我无法弄清楚为什么while循环不起作用。

Answer 1

我不确定你为什么要做这个循环，但尝试更简单，例如：

final int SIZE_OF_MARKSIX = 7;
final int SIZE_OF_PERIODS = 5;
int decision = 0;
Scanner input = new Scanner(System.in);

do
{

Set<Integer> ints = new HashSet<>();

for (int j = 0; j < SIZE_OF_PERIODS; j++) {
    String periodNumber = "";
    if (j == 0)
        periodNumber = "1st";
    else if (j == 1) {
        periodNumber = "2nd";
    } else if (j == 2) {
        periodNumber = "3rd";
    } else if (j == 3) {
        periodNumber = "4th";
    } else {
        periodNumber = "5th";
    }

    System.out.print("Please enter the past results of the " + periodNumber + " MarkSix: ");

    for (int i = 0; i < SIZE_OF_MARKSIX ; i++) {
        ints.add(input.nextInt());
    }

    System.out.println("");
}

Random rand = new Random();
List<Integer> randomInts = new ArrayList<>();

while (randomInts.size() < 6)
{
    int nextInt = rand.nextInt(49);
    if(!ints.contains(nextInt))
        randomInts.add(nextInt);
}
System.out.println(randomInts);
System.out.println("Do you want to have another set of numbers?(if yes, type 0)");  
decision = input.nextInt();

}while (decision==0); 

input.close();

我放了一组整数，这会保存你的输入，如果有人被重复，它就不会被保存。

我将一个整数列表作为结果，并随机编号。如果随机是在集合中，我跳过这个数字到下一个。如果我不接受这是一个很好的价值。

重复此操作，直到您有6个新号码。

最后记得关闭扫描仪。

你没有发现错误，好像有人写了字母而不是数字..小心。

此致

Answer 2

你输入带有k = j的while循环，所以你必须检查这不会发生，例如：

if(k!=j){
   while (theRandomNumber[k]==theRandomNumber[j]) {

        theRandomNumber[k] = rand.nextInt(49)+1;                
   }
}

while循环导致错误

2 个答案: