CodeWars算法 Twice linear 问题

Question

折腾了两天了，一直只是通过测试，但是提交的时候会出错，代码效率太差。求大神指点...

算法如下：

*"Consider a sequence u where u is defined as follows:

The number u(0) = 1 is the first one in u.

For each x in u, then y = 2 x + 1 and z = 3 x + 1 must be in u too.

There are no other numbers in u.

Ex: u = [1, 3, 4, 7, 9, 10, 13, 15, 19, 21, 22, 27, ...]

1 gives 3 and 4, then 3 gives 7 and 10, 4 gives 9 and 13, then 7 gives 15 and 22 and so on..."*

我的代码如下`

public static int dblLinear(int n)

{

    ArrayList<Long> arrayresult = new ArrayList<Long>();

    arrayresult.add((long) 1);

    //循环，生成这样的u[]数组。但是i太大的话，会超时

    for (int i = 1; i <= 15; i++)

    {

        arrayresult = CreateArrayList(arrayresult);

    }

    System.out.println(arrayresult.toString());

    long location = arrayresult.get(n);

    return  (int)location;

}

public static ArrayList<Long> CreateArrayList(ArrayList<Long> resultArray)

{

    ArrayList<Long> tmp = (ArrayList<Long>)resultArray.clone();

    for (long single : resultArray)

    {

        //按照规则，生成y和z。

        long y = single * 2 + 1;

        long z = single * 3 + 1;

        //看看y和z在不在数组里面，不在的话，添加进去。

        if (resultArray.indexOf(y) == -1)

        {

            tmp.add(y);

        }

        if (resultArray.indexOf(z) == -1)

        {

            tmp.add(z);

        }

    }

    Collections.sort(tmp);

    return tmp;

}

public static void main(String[] args)

{

    System.out.println(DoubleLinear.dblLinear(100));

}`

提示错误："Process was terminated. It took longer than 10000ms to complete

0 Passed"

如果循环的i设置的小，那么数组里面的数字也不完整。归根到底，还是代码效率太差...求指导啊

Answer 1

function dblLinear(n) {&nbsp; &nbsp; // your code&nbsp; &nbsp; var arr=[1];&nbsp; &nbsp; var y=0;&nbsp; &nbsp; var z=0;&nbsp; &nbsp; while(arr.length<=n){&nbsp; &nbsp; &nbsp; if(arr[y]*2 +1 < arr[z] *3 +1){&nbsp; &nbsp; &nbsp; &nbsp; arr.push(arr[y]*2 +1);&nbsp; &nbsp; &nbsp; &nbsp; y++;&nbsp; &nbsp; &nbsp; }else if(arr[y]*2 +1 > arr[z] *3 +1){&nbsp; &nbsp; &nbsp; &nbsp; arr.push(arr[z]*3 +1);&nbsp; &nbsp; &nbsp; &nbsp; z++;&nbsp; &nbsp; &nbsp; }else{&nbsp; &nbsp; &nbsp; &nbsp; y++;&nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; return arr[n];}javascript写的。