Question

我想在方法中使用ArrayList来使用Hailstone序列（http://plus.maths.org/content/mathematical-mysteries-hailstone-sequences），并使用该方法在用户输入数字后打印出所有步骤。这就是我现在所拥有的：

public static ArrayList<Integer> getHailstonSequence(int n){
    ArrayList<Integer> numbers = new ArrayList<Integer>();
    numbers.add(n);
    while(n != 1){
        if(n%2 == 0){
            System.out.print(n + " is even so I take half ");
            n = n/2;
            System.out.println(n);
        } else{
            System.out.print(n + " is odd so I make 3n+1 ");
            n = (n*3)+1;
            System.out.println(n);
        }
    }
    return getHailstonSequence(n);
}

public static void main(String [] args){
    Scanner keyboard = new Scanner(System.in);
    System.out.println("What is your number?");
    int n = keyboard.nextInt();
}

谢谢！

对于任何误解，我们深表歉意。

我要做的是从用户创建一个程序编号，然后显示该编号的Hailstone序列。练习假设使用Arraylist。再次抱歉任何误解，我不是故意让任何人生气。

Answer 1

public class Test {

  public static void main(String[] args) throws Exception {
    Scanner keyboard = new Scanner(System.in);
    System.out.println("What is your number?");
    int n = keyboard.nextInt();
    ArrayList<Integer> result =  getHailstonSequence(n);
    System.out.println(result);
  }

  public static ArrayList<Integer> getHailstonSequence(int n) {
    ArrayList<Integer> numbers = new ArrayList<Integer>();
    numbers.add(n);
    while (n != 1) {
      if (n % 2 == 0) {
        System.out.print(n + " is even so I take half ");
        n = n / 2;
        System.out.println(n);
      }

      else {
        System.out.print(n + " is odd so I make 3n+1 ");
        n = (n * 3) + 1;
        System.out.println(n);
      }
      numbers.add(n);
    }
    return numbers;
  }
}

在程序Java中使用ArrayLists

1 个答案: