2714
2714
Size of grid in squares.
2719
You have a grid of squares. Your job is to draw lines between the
2720
centres of horizontally or vertically adjacent squares, so that the
2721
lines form a single closed loop. In the resulting grid, some of the
2722
squares that the loop passes through will contain corners, and some
2723
will be straight horizontal or vertical lines. (And some squares can
2724
be completely empty - the loop doesn't have to pass through every
2727
Some of the squares contain black and white circles, which are clues
2728
that the loop must satisfy.
2730
A black circle in a square indicates that that square is a corner,
2731
but neither of the squares adjacent to it in the loop is also a
2734
A while circle indicates that the square is a straight edge, but _at
2735
least one_ of the squares adjacent to it in the loop is a corner.
2737
(In both cases, the clue only constrains the two squares adjacent
2738
_in the loop_, that is, the squares that the loop passes into after
2739
leaving the clue square. The squares that are only adjacent _in the
2740
grid_ are not constrained.)
2742
Credit for this puzzle goes to Nikoli, who call it `Masyu'. [19].
2744
Thanks to James Harvey for assistance with the implementation.
2746
[19] http://www.nikoli.co.jp/en/puzzles/masyu/
2750
Click with the left button on a grid edge to draw a segment of the
2751
loop through that edge, or to remove a segment once it is drawn.
2753
Drag with the left button through a series of squares to draw more
2754
than one segment of the loop in one go. Alternatively, drag over an
2755
existing part of the loop to undraw it, or to undraw part of it and
2756
then go in a different direction.
2758
Click with the right button on a grid edge to mark it with a cross,
2759
indicating that you are sure the loop does not go through that edge.
2760
(For instance, if you have decided which of the squares adjacent
2761
to a white clue has to be a corner, but don't yet know which way
2762
the corner turns, you might mark the one way it _can't_ go with a
2765
Alternatively, use the cursor keys to move the cursor. Use the Enter
2766
key to begin and end keyboard `drag' operations. Use the Space key
2767
to cancel the drag. Use Ctrl-arrowkey and Shift-arrowkey to simulate
2768
a left or right click, respectively, on the edge in the given
2769
direction relative to the cursor, i.e. to draw a segment or a cross.
2771
(All the actions described in section 2.1 are also available.)
2773
36.2 Pearl parameters
2775
These parameters are available from the `Custom...' option on the
2780
Size of grid in squares.
2784
Controls the difficulty of the generated puzzle.
2716
2786
Appendix A: Licence
2717
2787
-------------------
2719
This software is copyright 2004-2010 Simon Tatham.
2789
This software is copyright 2004-2012 Simon Tatham.
2721
2791
Portions copyright Richard Boulton, James Harvey, Mike Pinna, Jonas
2722
2792
Koelker, Dariusz Olszewski, Michael Schierl, Lambros Lambrou and
added
removed
puzzles.txt
