#### Ezra Pound

##### Well-Known Member

As the festive season is upon us, I though I would submit a puzzle, it was though up by the GCHQ staff

Explaining how to get started, the GCHQ website states: "In this type of grid-shading puzzle, each square is either black or white. Some of the black squares have already been filled in for you.

"Each row or column is labelled with a string of numbers. The numbers indicate the length of all consecutive runs of black squares, and are displayed in the order that the runs appear in that line.

"For example, a label "2 1 6" indicates sets of two, one and six black squares, each of which will have at least one white square separating them."

Puzzle website link here :-

First thoughts, it would be possible to write a program to 'score' every possible combination of black on white squares, however my calculator won't tell me what 2's 625th power is, so I'm guessing it's not a small number

EDIT

It's 1.392346 e+188 combinations for the whole square, I think calculating single rows at 33,554,432 combinations could be done, but there will be more than one solution for a single row/column - Doh ! !

Explaining how to get started, the GCHQ website states: "In this type of grid-shading puzzle, each square is either black or white. Some of the black squares have already been filled in for you.

"Each row or column is labelled with a string of numbers. The numbers indicate the length of all consecutive runs of black squares, and are displayed in the order that the runs appear in that line.

"For example, a label "2 1 6" indicates sets of two, one and six black squares, each of which will have at least one white square separating them."

Puzzle website link here :-

**http://www.gchq.gov.uk/SiteCollectionImages/grid-shading-puzzle.jpg**First thoughts, it would be possible to write a program to 'score' every possible combination of black on white squares, however my calculator won't tell me what 2's 625th power is, so I'm guessing it's not a small number

EDIT

It's 1.392346 e+188 combinations for the whole square, I think calculating single rows at 33,554,432 combinations could be done, but there will be more than one solution for a single row/column - Doh ! !

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