Please tell me whether I am correct or not with the following line.  int x = ((int)(Math.random() * 100000)) % 1000;   This line always give me a 3 digit number 100 to 999 ?  Is there an easier way to type this out? Did I over complicate this code?
4701
How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.
54893
Is it possible to pick a random natural number? How about a random real number? Is the axiom of choice involved in this?
28516
How do I format a number in Java? What are the &quot;Best Practices&quot;? Will I need to round a number before I format it?  32.302342342342343 =&gt; 32.30 .7323 =&gt; 0.73  etc.
58615
Have you ever tried this before?  static void Main(string[] args) {     int x = 10;     x = x++;     Console.WriteLine(x); }   Output: 10.  but for   static void Main(string[] args) {     int x = 10;     x++;     Console.WriteLine(x); }   Output: 11.  Could anyone explain why this?
67663
Can anything be stated about the distribution of the digits of Pi, i.e., if I were to sample n digits of Pi, can anything be said about the probability to observe certain digits, or is there any reason to assume that they would not be evenly distributed? This is purely a curiosity question.
93853
How would you go about creating a random alpha-numeric string that matches a certain regular expression?  This is specifically for creating initial passwords that fulfill regular password requirements.
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This is a wild one: can anyone write a code that converts a number into the corresponding word? e.g.:  4 -&gt; 'four' 31 -&gt; 'thirty-one'   and so on. Obviously, it is not enough to build an array in which you can store the numbers and the word associated with it and then just print instead of the number the stored word. What complicates matters more, are numbers like 11 ('eleven'). I intend to use it for numbering equations. So, anybody up to it?
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I understand the use of pseudo-random number generators. I am not getting mixed up between these and "real" random number generators.  However, I don't understand for what a real random number generator is used. If it is not deterministic, how can it be used in an algorithm?
109203
I was reading the Math.random() javadoc and saw that random is only psuedorandom.    Is there a library (specifically java) that generates random numbers according to random variables like environmental temperature, CPU temperature/voltage, or anything like that?
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Is there a reasonable statistic test one can do to standard random number generators (say, one of those that come built in in Python libs) which shows they are not really random?  (By reasonable I mean to exclude silly things like «generate a looong list and see that it is periodic»)  Later: Notice I am looking for a test that fails on standard generators.
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This prints 83  System.out.println(0123)   However this prints 123  System.out.println(123)   Why does it work that way?
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Do you a digit efficient way to approximate $\pi$? I mean representing many digits of $\pi$ using only a few numeric digits and some sort of equation. Maybe mathematical operations also count as penalty.  For example the well known $\frac{355}{113}$ is an approximation, but it gives only 7 correct digits by using 6 digits (113355) in the approximation itself. Can you make a better digit ratio?  EDIT: to clarify the "game" let's assume that each mathematical operation (+, sqrt, power, ...) also counts as one digit. Otherwise one could of course make artifical infinitely nested structures of operations only. And preferably let's stick to basic arithmetics and powers/roots only.  EDIT: true. logarithm of imaginary numbers provides an easy way. let's not use complex numbers since that's what I had in mind. something you can present to non-mathematicians :)
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Hey all I asked this over  =) and I got a good answer but I still have no idea whats going on. I want to know how the expression got to the answer and maybe the math behind how it was reasoned.. the steps if you would be so kind. The likelihood is I don't understand the equation.   I'm not a big maths person please be gentle :p     For all those playing along at home I'm reading Absolute Java 5th   Edition by Walter Savitch (Chapter 2 Page 66).      The Expression  double d = 12345.123456789; System.out.printf("START%12.5e END %n", d);       The Answer  START 1.23451e+04END       I understand the basic principles of this printf method's arguments   for example I know the '%' represents the start of the parameters.   '12' is the number of spacing, '.5' is the times the decimal point   will move.... I see the decimal point has moved 4 places towards the   left... can someone explain the principles of e-notation. Also how   this expression came to this answer =).      As far as e-notation go's its meant to be scientific notation;      So like 5.89e-4 would mean 0.000589 (move the decimal place if minus   left if not move the decimal place right).
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Ok I hope I am mising something here as I really don't want this to be a bug.   The following piece of code returns 2. Per my understanding of the ceiling functionality, the result should be 3 because 7/3 is roughly 2.33333 and the ceiling should return 3.   Is this a bug or am I missing something? Thanks.   Integer pageNumber = (Integer) Math.ceil(7/3);   This returns 2 and not 3 as expected.   It works fine on other input. For example:  Integer pageNumber = (Integer) Math.ceil(8/5);   This returns 2 as expected.
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So I'm supposed to express:  $$1.24\overline{123}=1.24\;123\;123\;123\;\ldots$$ as the ratio of two integers.  So I got $$1+\frac{24}{100}+\frac{123}{10^5}+\cdots$$  I don't know if this is correct, and if it is, I also don't know how I would get the common ratio from this. Would the common ratio just be $\frac{1}{10^5}$? Am I doing this wrong?
109402
The probability that a $k$-digit number does NOT contain the digits   0,5 or 9         $0.3^k$   $0.6^k$   $0.7^k$   $0.9^k$      I'm confused since the question has asked the number should not contain 0,5 OR 9. So, should the answer be $0.9^k$ or something else?
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My friend thought of a system in which each number $n$ (I will first restrict my question to positive integers $n$) is represented by a digit string $(d_l,...,d_1)$ as follows $\forall n \in \mathbb{N}, \exists l \in \mathbb{N}: n = (d_l, d_{l-1}, ..., d_2, d_1) = \sum_{i=1}^l (d_i*(i!))$ where $\forall i \in \mathbb{N}, d_i \in \mathbb{N}: d_i \leq i$ and specifically $\forall i&gt;l, d_i = 0$ ; note that each integer $d_i$ would be represented in decimal with at least 1 digit (in general, these factorial digits can be quite long in decimal representation)- but this is not an issue at the moment [because his system uses a finite alphabet via balanced quinary for each $d_i$].  [In this post, any number shown is in decimal.]  For example, $$1729=2*6! + 2*5! + 2*4! + 1=(2,2,2,0,0,1)$$ and $$1729^3 = (10*12!+9*11!+5*10!+3*9!+6*8!) + 1729 = (10, 9, 5, 3, 6, 0,2,2,2,0,0,1)$$.  My question is: how would this digit string $(d_l,...,d_1)$ be computed most efficiently for general positive integer n? I have mostly just been trying to guess at the largest $l \in \mathbb{N}: l*(l!) \leq n, (l+1)! &gt; n$ and then (once I have found it), I just go through digit-by-digit, working my way down in values of candidate $d_i$ (mostly by squeeze theorem with the goal of finding out that $d_i + 1$ is too large first and then next testing $d_i$ and finding that it works). This process can be quite arduous. What would you recommend doing, algorithmically and efficiently? Bragging rights for Mathematica code that automates the process.  (Using Stirling's formula might be helpful, but it still requires a lot of playing around.)  What modifications would need to be made for general real numbers (including nonintegers)? After the radix point, it works similarly, but with $(i!)^{-1}$ (where, I think, $d_i&lt;i \forall i \in \mathbb{N}$ and where the first such base is $\frac{1}{2!}$).  More generally and philosophically, are there any spiritual problems with this representation? It is meant to be rather compact and alien. What are some cool properties that it exhibits?