A blog reader asked me if I had plans to release a new 64bit-community wrapper… Indeed I have plans to do so, just did not have time so far to compile a new package. So here it goes:

As always, I don’t guarantee anything, so please note:

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So recently I stumbled across a programming quiz to which I later returned because it somehow fascinated me.

### Problem

Finding the first available number (or the smallest missing number) in a list is a common problem in Computer Science (for example for Defragmenting or generating keys) and describes the search for the smallest natural number, which is not part of a set X of natural numbers. X is a set of distinct natural numbers (and being a set, is not ordered).

**We are now looking for a function with linear worst-case time complexity O(n).**

### Example

We define X as a set of distinct natural numbers:

X = {23,9,12,0,11,1,13,7,21,14,5,4,17,19,3,6,2}

So in this set, we find that the number **8** is the first available number (smallest missing number). So running the algorithm over the above set should return 8.

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After fiddling with the NMAKE file and a nudge from a nice commenter, I hereby provide the latest version of the Tanuki Service Wrapper for Windows x64.

As always, I don’t guarantee anything, so please note:

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After quite a long time, Tanuki Software released another two versions of the Tanuki Service Wrapper. I hereby provide a build of the latest version of the wrapper, version 3.5.19.

As always, I don’t guarantee anything, so please note:

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Recently, Tanuki Software released a new version of the Tanuki Service Wrapper (version 3.5.16). I am happy to make a compiled version of the Tanuki Service Wrapper for Windows Server (64-bit) available to you.

As always, I don’t guarantee anything, so please note:

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I always like comments in my blog and someone nicely asked if I could provide a new build for the Tanuki Service Wrapper for Windows x64 (Community Edition). Sure I can! Find the download link below.

As always, I don’t guarantee anything, so please note:

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Due to a a request, I am uploading a more **current version of the Tanuki Service Wrapper for Windows x64 **(Community edition). I used these instructions to build the wrapper. Find the download link below.

As always, I don’t guarantee anything, so please note:

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For an university assignment, I had to implement a **recursive function to calculate the digit sum** of a given number. I place my solution here for my own reference:

```
public static int digitSum(int n) {
if(n < 10)
return n;
else
return n % 10 + digitSum(n / 10);
}
```

This code can also be found in the GitHub repository that I am keeping for university: ChecksumTool.java

When comparing floating-point numbers (float, double) in Java, we quickly discover that we get **roundoff errors**. This has to do with the limited precision of Java floating point variables. The following code example shows the problem at hand:

```
double r = Math.sqrt(2);
double d = r * r - 2;
if (d == 0)
System.out.println("sqrt(2) squared minus 2 is 0");
else
System.out.println("sqrt(2) squared minus 2 is not 0 but " + d);
```

Theoretically, `d`

should be 0, but because we have **limited precision** (see the documentation on primitive data types) there will be a difference:

sqrt(2) squared minus 2 is not 0 but 4.440892098500626E-16

One possibility to circumvent this problem is to **define a constant value** (the following example uses `EPSILON`

). We then check if the difference is smaller than that constant value. Since we received a very small number (4.4E-16) above, we can use 1E-14 as the value of our constant:

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