Is it possible to get an approximation to a seed based on a finite sequence of pseudo random numbers?

Question

suppose I have some numbers that form a series for example: 652,328,1,254 and I want to get a seed that if I, for example, do

srand(my_seed);

I will get some kind of approximation with bounded error to my origonal sequence, when all numbers appearing in the same order.

Answer 1

이 방법을 사용하여 일부 JavaScript를 호출 할 수 있습니다.

http://blogs.msdn.com/B / InfoPath / Archive / 2005 / 06 / 17 / 430347.aspx

호출 할 스크립트는 이와 같을 것입니다 (제거 할 버튼에 맞게 편집) :

<script type="text/javascript">

    function HideDeleteOption() 
    {
        try {
document.getElementById("Ribbon.ContextualTabs.InfoPathListDisplayTab.Manage.Controls.btnDelete-Medium").style.display = "none";
        }
        catch (ex) 
        {
        }
    }

    function HideEditDeleteOption() 
    {
        try {                
  document.getElementById("Ribbon.ContextualTabs.InfoPathListTab.Actions").style.display = "none"
        }
        catch (ex) 
        {
        }
    }

    setTimeout("HideDeleteOption();", 100);
    setTimeout("HideEditDeleteOption();", 100);

.

Answer 2

You can't have an error bound in general. Either your algorithm works or it doesn't. The reason for this is that a reasonable error bound is obviously much smaller that RAND_MAX. That in turn means that the the low bits are not as random as the higher bits. But a good PRNG makes certain that all bits are equally random.

Consider this slow but mathematically sound example of an RNG algorithm:

int rand() {
  state = AES_encrypt(state);
  return state % RAND_MAX;
}
void srand(int seed) {
  state = AES_encrypt(seed);
}

If you can find any significant correlation between the output sequence and the previous state, the AES algorithm should be considered broken.

Answer 3

Check out this question.

Like Justin says, it's possible to backtrack a linear congruent generator (which rand() implementations often are) when you have a sequence of generated numbers. I guess the problem is to know which one of the previous values is the original seed...

Answer 4

사용자 정의 양식 템플릿 사용자 지정 listfielditerator . 이렇게하면 양식이 렌더링되는 방식보다 완전한 Controle이 있고 Bewer의 코드에서 C #을 사용할 수 있습니다.

컨트롤은 형식 내에서 디스플레이에 대한 항목 필드를 열거하는 데 사용됩니다. 이 컨트롤은 % ProgramFiles % \ Common Files \ Microsoft Shared \ Web Server Extensions \ 14 \ 14 \ 템플릿 \ Contrypemlates 디렉토리에있는 % ProgramFiles.Ascx 파일에있는 DefaultTemplates.Ascx 파일에 정의 된 일련의 중첩 된 제어 템플릿을 통해 목록 항목 양식에 삽입됩니다.

Nice 자습서 사용자 정의 listfielditerator ~ http://msdn.microsoft.com/en-us/library /aa543922%28v=office.14%29.aspx "rel="nofollow "> 유효성 검사, 렌더링, 수영렬 etc