prob021: crossfigures

proposed by Toby Walsh
tw@cs.york.ac.uk

Specification

Crossfigures are the numerical equivalent of crosswords. You have a grid and some clues with numerical answers to place on this grid. Clues come in several different forms (for example: Across 1. 25 across times two, 2. five dozen, 5. a square number, 10. prime, 14. 29 across times 21 down ...).