Picture logic puzzles a.k.a. Nonograms, Hanjie, Cross Numbers, Picross, or Griddlers, are grid-based problems where the objective is to paint specific cells and leave the rest blank based on the numerical clues provided to the top and left of the grid to reveal a hidden pixel image.

These are often black and white but may have colored variations as well to increase the complexity of the puzzle and amplify the gameplay.

You’ve to paint cells such that the length and sequence match the clues, and there’s at least a single cell space between adjacent squares. Solving techniques may include different tried-and-tested methods but never guesswork. These rule-based techniques include simple boxes, simple spaces, forcing, and contradiction, etc. If not these, the best-first trick also works. However, every method needs a lot of practice and patience.

There’s no technique to determine the difficulty of the puzzle. But, the ratio between the size and length and the size itself can indicate how tough it would be. In simple words, the more the pixels, the harder the puzzle.

So, several rules can be employed to solve Hanjie puzzles, and here we discuss a few important ones.

Hanji Solving Techniques

Simple boxes: Starting from somewhere in between, leaving two spaces on the right border to the left and two spaces on the left border to the right, is the simplest method using the conjunction of possible spaces for each block.

Simple spaces: Here you determine spaces by seeking cells that are out of range of the likely blocks of the boxes.

Forcing: This technique shows the importance of spaces as placed somewhere in the middle of a row forcing a large block on either side. If there’s a small gap, fill that as well with spaces.

Glue: At times, there may be a box near the border not too far from the edge than the length of the initial clues. So, this clue will spread through the box, forcing it outwards from the edge.

Punctuating: Enclose each completed block by separating spaces as per the Simple Spaces technique. This results in Forcing which takes you several steps ahead in the game.

Mercury: If there’s a box in a row with equal distance from the edge as the length of the initial clue, the first cell will then be a space. Moreover, when the box is a block of boxes to the right, more spaces will be there in the beginning.

Contradictions: This one’s a useful advanced-level technique when you exhaust the basic ones. Here you try an empty cell to be a box, and if there’s an error, understand that the tried cell will be a space.

Nonograms or Hanji can also be solved efficiently in computing as the interconnected constraints on the two axes enable the space to be confined, reducing the space that must be searched for a solution.

So, here we conclude the explanation of the rule-based Hanji solving technique for all you Hanji enthusiasts. Test your skills with this, and see how far you go!