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Nonogram

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A nonogram is a sophisticated picture logic puzzle.

Nonogram wiki
Nonogram wiki

These puzzles use a grid of cells to hide a secret image. To find it, you must color certain cells or leave them blank. The clues are numbers located at the edges of the grid. These numbers represent a form of discrete tomography. This means they measure the unbroken lines of filled squares in any row or column. For example, a clue of "4 8 3" tells you there are sets of four, eight, and three filled squares. You must place at least one blank square between each set. While many puzzles are binary, meaning they use only black and white, others use colors. In colored versions, the clues are also colored to guide the player.

Solving a nonogram requires strict logical reasoning rather than guesswork.

Paint by numbers Animation
Paint by numbers Animation

If you guess and make a single error, it can ruin the entire solution. This error might not appear until much later, making it very difficult to correct. Solvers often use a dot or a cross to mark cells they are certain are empty. You can often complete a puzzle by analyzing one row or column at a time. However, more difficult puzzles require "what if" reasoning. This involves looking at multiple rows or columns to find contradictions. For instance, if a specific cell being filled would cause an error elsewhere, that cell must be a space.

There are several specific techniques used to solve these grids. The "Simple Boxes" method involves finding where blocks of squares must overlap. In a row of ten cells with a single clue of 8, the block must cover the six centermost cells. The "Simple Spaces" method identifies cells that are out of range for any possible block. Another technique is "Forcing," where a confirmed space limits where a block can fit. For example, a gap too small for a clue must be filled with spaces. The "Glue" technique helps when a box near a border forces a clue to align with that edge. Finally, the "Joining and Splitting" method uses logic to decide if two blocks should be connected or separated.

Paint by numbers - Solving - Example1
Paint by numbers - Solving - Example1

The history of the nonogram began in Japan during the late 1980s. In 1987, a Japanese graphics editor named Non Ishida won a competition in Tokyo. She designed grid pictures inspired by the lights of skyscrapers being turned on or off. Around the same time, a professional puzzler named Tetsuya Nishio independently invented similar puzzles. In 1988, Ishida published her work as "Window Art Puzzles." A puzzle collector named James Dalgety helped her share these puzzles globally. Dalgety created the name "nonogram" by combining "Non" with the word "diagram."

Paint by numbers - Solving - Example2
Paint by numbers - Solving - Example2

The popularity of nonograms grew through various print and electronic media. In 1990, The Sunday Telegraph began publishing them weekly in the United Kingdom. By 1993, Ishida published the first dedicated book of nonograms in Japan. In 1998, a competition held by The Sunday Telegraph resulted in readers choosing "Griddlers" as a new name. The puzzles eventually spread to many countries, including Sweden, the United States, and South Africa. Today, magazines containing these puzzles are published in nations like Italy, Germany, Russia, and Israel.

Paint by numbers - Solving - Example3
Paint by numbers - Solving - Example3

Electronic versions of the puzzle became common by 1995 on handheld devices like the Game Boy. Nintendo trademarked the name "Picross," which is short for "picture crossword." They released many titles, including nine for the Super Famicom. The developer Jupiter Corporation has been very prolific with the series. They released Picross DS for the Nintendo DS in 2007, and many more for the 3DS and Nintendo Switch. These include special character-themed versions featuring Pokémon, Zelda, and Sanrio characters.

Paint by numbers - Solving - Example4
Paint by numbers - Solving - Example4

Nonograms connect to many different digital and social experiences. Beyond dedicated consoles, they appear in mobile games like "Paint it Back," which focuses on restoring an art gallery. Some PC games, such as "Pictopix," allow players to share their own creations. The puzzles have even appeared in large role-playing games like "Runescape" during special events. Because they have no theoretical limits on size or layout, they continue to evolve. Whether called Griddlers, Picross, or StarPic, they remain a global phenomenon for logic enthusiasts.

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🖼️ Images & Media (12)
File:Nonogram wiki.svg
Nonogram wiki.svg
File:Paint by numbers Animation.gif
Paint by numbers Animation.gif
File:Paint by numbers - Solving - Example1.png
Paint by numbers - Solving - Example1.png
File:Paint by numbers - Solving - Example2.png
Paint by numbers - Solving - Example2.png
File:Paint by numbers - Solving - Example3.png
Paint by numbers - Solving - Example3.png
File:Paint by numbers - Solving - Example4.png
Paint by numbers - Solving - Example4.png
File:Paint by numbers - Solving - Example5.png
Paint by numbers - Solving - Example5.png
File:Paint by numbers - Solving - Example6.png
Paint by numbers - Solving - Example6.png
File:Paint by numbers - Solving - Example7.png
Paint by numbers - Solving - Example7.png
File:Paint by numbers - Solving - Example8.png
Paint by numbers - Solving - Example8.png
File:Paint by numbers - Solving - Example9.png
Paint by numbers - Solving - Example9.png
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Mathematical approach.png
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