Nonogram
Nonograms, also known as Hanjie, Paint by Numbers, Picross, Griddlers, and Pic-a-Pix, are picture logic puzzles in which cells in a grid must be colored or left blank according to numbers at the edges of the grid to reveal a hidden picture.
In this puzzle, the numbers are a form of discrete tomography that measures how many unbroken lines of filled-in squares there are in any given row or column.
In 1987, Non Ishida, a Japanese graphics editor, won a competition in Tokyo by designing grid pictures using skyscraper lights that were turned on or off.
Coincidentally, a professional Japanese puzzler named Tetsuya Nishio invented the same puzzles independently, and published them in another magazine.
In 1990, James Dalgety in the UK invented the name Nonograms after Non Ishida,[citation needed] and The Sunday Telegraph started publishing them on a weekly basis.
Nonograms were also published in Sweden, the United States (originally by Games magazine[3]), South Africa and other countries.
Nintendo picked up on this puzzle fad and released two "Picross" (picture crossword) titles for the Game Boy and nine for the Super Famicom (eight of which were released in two-month intervals for the Nintendo Power Super Famicom Cartridge Writer as the NP series) in Japan.
Since then, one of the most prolific Picross game developers has been Jupiter Corporation, who released Picross DS on the Nintendo DS in 2007, 8 titles in the Picross e series for the Nintendo 3DS eShop (along with 5 character-specific titles, including ones featuring Pokémon, Zelda and Sanrio characters), and 9 titles in the Picross S series for the Nintendo Switch (along with two character-specific ones featuring Kemono Friends and Overlord respectively, and another featuring intellectual properties from Sega's Master System and Genesis).
Increased popularity in Japan launched new publishers and by now there were several monthly magazines, some of which contained up to 100 puzzles.
In 2013, Casual Labs released a mobile version of these puzzles called Paint it Back with the theme of restoring an art gallery.
Released early in 2017, Pictopix has been presented as a worthy heir to Picross on PC by Rock, Paper, Shotgun.
Magazines with nonogram puzzles are published in the US, UK, Germany, Netherlands, Italy, Hungary, Finland, the Czech Republic, Slovakia, Russia, Ukraine, and many other countries.
If guessing is used, a single error can spread over the entire field and completely ruin the solution.
The hidden picture may help locate and eliminate an error, but otherwise it plays little part in the solving process, as it may mislead.
For example, in a row of ten cells with only one clue of 8, the bound block consisting of 8 boxes could spread from As a result, the block must spread through the six centermost cells in the row.
This method consists of determining spaces by searching for cells that are out of range of any possible blocks of boxes.
A space placed somewhere in the middle of an uncompleted row may force a large block to one side or the other.
If there is a box in a row that is in the same distance from the border as the length of the first clue, the first cell will be a space.
In some cases, reasoning over a set of rows may also lead to the next step of the solution even without contradictions and deeper recursion.
[5][6][7] This means that there is no polynomial time algorithm that solves all nonogram puzzles unless P = NP.
[8] An extensive comparison and discussion of nonogram solving algorithms is found at the WebPBN site (Web Paint-By-Number).
[9] A nonogram solver written in C++ and published in the journal Pattern Recognition solves lines in quadratic time at most.
[10] Nintendo has published several nonogram video games using the name "Picross" (ピクロス, Pikurosu).
However, the game failed to become a hit in the U.S. market, despite a heavy advertising campaign by Nintendo.
Picross 2 was released later for Game Boy and Mario's Super Picross for the Super Famicom, neither of which were translated for the U.S. market (Mario's Super Picross was, however, later released on the Wii Virtual Console's PAL service on September 14, 2007, as part of its Hanabi Festival, as well as on the Nintendo Switch Online service worldwide on September 23rd, 2020[11]).
Both games introduced Wario's Picross as well, featuring Mario's nemesis in the role.
A hint is available before starting the puzzle in all modes; the game reveals a complete row and column at random.
Picross DS was released in Europe and Australia on 11 May 2007 and in the United States on July 30, 2007 and has been received well by critics, including Craig Harris,[12] Jessica Wadleigh[13] and Dave McCarthy [14] labelling the game "Addictive".
[15][16] A 3D version of the game, titled Picross 3D, was also released for the DS in Japan in 2009 and internationally in 2010.
Other companies have also released nonogram video games, such as Falcross[18] on iOS, Across-Stitch by Knitwit Studios on Microsoft Windows and Apple macOS, and the Color Cross series of games by Little Worlds Studio on the Nintendo DS, Microsoft Windows, and iOS.
