Shikaku (Off-by-One) (559)

Other names: Shikaku Liars, Wrong shikaku

Divide the grid into rectangles along the grid lines such that each cell is in exactly one rectangle and each rectangle contains exactly one given number. The number must be exactly 1 more or 1 less than the area of the rectangle (in cells). A square is considered a rectangle for purposes of these instructions.

Reference: WPF (1)