Off-by-One Error

A computer wrote these logic puzzles, but they’re all a little bit wrong. All given numbers in every odd column and every odd row might be shifted up by 1.

For example, when I generated a mini-sudoku, I received this invalid puzzle:

The givens in Row 3, Column 1 and Column 5 were shifted. What I was meant to see was:

Skyscraper

• A number between 1 and 9 (inclusive) must appear in each cell
• Each row and column must be full of unique numbers
• Numbers in each cell represents the “height” of a skyscraper in that cell
• The number on either side of each row and column represents how many skyscrapers one would see from that vantage point, where taller skyscrapers block the view of shorter skyscrapers
• E.g. If the numbers in the first row were “3 5 4 1 2”, the number on the left side would be 2 (because one would see skyscrapers of height 3 and 5), and the number on the right side would be 3 (because one would see skyscrapers of height 2, 4, and 5)

Killer Sudoku

• A number between 1 and 9 (inclusive) must appear in each cell
• Each row, column, and nonet must be full of unique numbers
• The grid is separated into “cages”
• The numbers inside cages must sum to the number written in its top-left corner
• Cages contain unique numbers

Grayscale image

Shikaku

• Board must be divided into rectangles
• Exactly 1 number must be inside each rectangle
• The area of each rectangle must be equal to the number inside it

Slitherlink

• If a cell contains a number, the amount of lines around the cell must be equal to it
• Lines may not branch (i.e. create a T-shape) nor intersect (i.e. create a plus-shape)
• Line must form a single continuous loop