Medium Nonogram Puzzles

About Nonogram Puzzle

A Nonogram (also known as Picross, Griddler, Japanese Crossword or Paint-by-Numbers) is a logic puzzle where the solver fills a grid based on numerical clues provided for each row and column. The numbers indicate the lengths of consecutive filled blocks in that row or column. The goal is to reveal a hidden picture by correctly shading the grid.

Basic Rules / How to Play

• Grid Structure: The puzzle consists of a blank grid (usually ranging from 5×5 to 25×25 or larger). Each row and column has a sequence of numbers indicating the lengths of consecutive filled blocks. Example: A row clue 3 1 means there are two groups of filled squares: first a block of 3, then a block of 1, separated by at least one empty space.
• Filling the Grid: Black squares represent filled blocks. White squares represent empty spaces (sometimes marked with an "X"). The numbers on the edges describe the exact order of filled blocks.
• Constraints: Blocks must appear in the exact order given. There must be at least one empty square between different blocks. The puzzle is solved when all row and column clues are satisfied.

Solving Tips and Techniques:

• Complete Lines: If the sum of all blocks plus required gaps equals the grid size, fill them in order. For example, in a 5-cell row with the clue 5, all five cells must be filled.
• Overlapping: For a block of size B in a row/column of length N, some squares must be filled if the block cannot fit elsewhere. For example, A 4 in a 5-cell row means the middle three squares must be filled (since the block can't fit at either end without overlapping).
• Edge Filling: If a block starts at the edge, shade the required squares. For example, A 3 in a 5-cell row starting from the left means the first three squares are filled.
• Elimination: Mark empty squares where blocks cannot possibly fit. Example: If a 2 is already placed in a row, mark the adjacent squares as empty.
• Joining and Splitting: If two possible block positions overlap in some squares, those squares must be filled. Example: If a 3 can start at position 2 or 3 in a row, the third square must be filled.
• Cross-Reference: Cross-reference filled squares in rows and columns to eliminate possibilities.
• Pencil Marking: Temporarily mark possible positions for uncertain blocks. Eliminate contradictions by checking against other rows/columns.
• Hypothesis Testing: For very complex puzzles, make an educated guess and backtrack if a contradiction arises.

Nonogram puzzles need careful looking, logical thinking, and spotting patterns. The more you practice, the faster and better you'll get at solving them. Have fun!