## JSweeper

Adding to my collection of clones of popular, well-known games, I created back in November of 2016 a Java-implementation of the all-time Windows classic game, Minesweeper.

Minesweeper was pre-installed on every installation of Windows up to and including Windows 7 and has been ported to a variety of different systems. Because of this, nearly everyone has at least once in their life played Minesweeper or at least heard of it.
In Minesweeper you are presented with a square grid of covered tiles containing either numbers or mines. Your task is it to uncover all tiles which are not mines in the least amount of time. When you uncover a mine, it explodes and the game is lost. To aid in figuring out which tiles are mines and which are not, every tile that is not a mine tells you how many mines are in the neighbouring eight tiles. Tiles which have no neighbouring mines are drawn gray and uncover neighbouring non-mine tiles once uncovered.
More on Minesweeper can be found in this Wikipedia article — I am linking to the German version, as the current English version has major flaws and lacks crucial information. If you are so inclined, feel free to fix the English Minesweeper Wikipedia article.

In my clone, there are three pre-defined difficulty levels, directly ported from the original Minesweeper game, and an option to freely adjust the board’s width and height as well as the number of bombs which will be placed. Gameplay is nearly identical to the original, as my clone also uses a square grid and the tile’s numbers correspond to the number of bombs in the eight tiles surrounding that tile.
The game has a purposefully chosen pixel-look using a self-made font to go along with the pixel-style.

#### Controls

• Arrow keys and enter to navigate the main menu
• Arrow keys or mouse movement to select tiles
• Space, enter or left-click to expose a tile
• ‘f’ or right-click to flag a tile
• ‘r’ to restart game when game is either won or lost
• F11 toggles fullscreen

To play the game, you can either download the .jar file or compile the source code for yourself. The source code is listed below and can be downloaded as a .java file.

// Java 1.6 / 1.8 code
// Jonathan Frech  5th of November, 2016
//         edited  7th of November, 2016
//         edited 11th of November, 2016
//         edited 13th of November, 2016
//         edited 14th of November, 2016
//         edited 15th of November, 2016
//         edited 17th of November, 2016
//         edited 19th of November, 2016
//         edited 19th of May     , 2017
//         edited 22nd of May     , 2017
//          * fixed max mine cap when
//            using custom settings

## A278328

The On-Line Encyclopedia of Integer Sequences (also known by its acronym, OEIS) is a database hosting hundreds of thousands of — as the name implies — integer sequences. Yet, despite the massive number of entries, I contributed a new integer sequence, A278328.

A278328 describes numbers whose absolute difference to their decimal reverse are square. An example would be $12$ or $21$ (both are the decimal reverse to each other), since $\left|12-21\right|=9$ and $9=3^2$.

Not a whole lot is known about the sequence, partly due to its definition only resulting in the sequence when using the decimal system, though it is known that there are infinitely many numbers with said property. Since there are infinitely many palindromes (numbers whose reverse is the number itself), $\left|n-n\right|=0$ and $0=0^2$.

Due to there — to my knowledge — not being a direct formula for those numbers, I wrote a Python script to generate them. On the sequence’s page, I posted a program which endlessly spews them out, though I later wrote a Python two-liner, which only calculates those members of the sequence in the range from $0$ to $98$ (shown below entered in a Python shell).

>>> import math
>>> filter(lambda n:math.sqrt(abs(n-int(str(n)[::-1])))%1 == 0, range(99))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 21, 22, 23, 26, 32, 33, 34, 37, 40, 43, 44, 45, 48, 51, 54, 55, 56, 59, 62, 65, 66, 67, 73, 76, 77, 78, 84, 87, 88, 89, 90, 95, 98]

## 4096

4096 is a Java-based clone of the well-known web and mobile game 2048, which itself clones 1024 and is similiar to THREES. The naming trend is quite obvious, though note that $2^{12}$ is a power of two where the exponent is divisible by three, futher connecting to the aforementioned game.

In the game, you are faced with a 4×4 matrix, containing powers of two. By swiping in the four cardinal directions (e.g. pressing the arrow keys), you shove all the non-empty cells to that side. When two equal powers of two collide, they fuse together, adding. Once you shoved, an empty tile pseudo-randomly transforms to either a two-tile (90%) or a four-tile (10%).
Your objective at first is to reach the tile 4096, though the real goal is to achieve the highest score. Your score is the sum of all the collisions you managed to cause.

To play 4096, you can either download the .jar file or review and compile the game for yourself, using the source code listed below.

#### Controls

• Up, down, left or right arrow key shoves the tiles
• Escape restarts the game upon a loss
• F11 toggles fullscreen

// Java 1.8 Code
// Jonathan Frech,  5th of December 2016
//          edited  6th of December 2016
//          edited  7th of December 2016
//          edited  8th of December 2016
//          edited  9th of December 2016
//          edited 19th of February 2017
//          edited 24th of February 2017
//          edited 28th of February 2017
//          * gave the 4096 tile a color
//          edited 22nd of April    2017
//          * fixed window positioning by changing
//            frame.setLocationRelativeTo(null); to
//            frame.setLocationByPlatform(true);