sgt-bridges - Bridge-placing puzzle
sgt-bridges [--generate n] [--print wxh [--with-solutions] [--scale n] [--colour]] [game-parameters|game-ID|random-seed]
You have a set of islands distributed across the playing area. Each island contains a number. Your aim is to connect the islands together with bridges, in such a way that:
There are some configurable alternative modes, which involve changing the parallel-bridge limit to something other than 2, and introducing the additional constraint that no sequence of bridges may form a loop from one island back to the same island. The rules stated above are the default ones.
Credit for this puzzle goes to Nikoli (http://www.nikoli.co.jp/en/puzzles/hashiwokakero.html (beware of Flash)).
Bridges was contributed to this collection by James Harvey.
To place a bridge between two islands, click the mouse down on one island and drag it towards the other. You do not need to drag all the way to the other island; you only need to move the mouse far enough for the intended bridge direction to be unambiguous. (So you can keep the mouse near the starting island and conveniently throw bridges out from it in many directions.)
Doing this again when a bridge is already present will add another parallel bridge. If there are already as many bridges between the two islands as permitted by the current game rules (i.e. two by default), the same dragging action will remove all of them.
If you want to remind yourself that two islands definitely do not have a bridge between them, you can right-drag between them in the same way to draw a ‘non-bridge’ marker.
If you think you have finished with an island (i.e. you have placed all its bridges and are confident that they are in the right places), you can mark the island as finished by left-clicking on it. This will highlight it and all the bridges connected to it, and you will be prevented from accidentally modifying any of those bridges in future. Left-clicking again on a highlighted island will unmark it and restore your ability to modify it.
You can also use the cursor keys to move around the grid: if possible the cursor will always move orthogonally, otherwise it will move towards the nearest island to the indicated direction. Holding Control and pressing a cursor key will lay a bridge in that direction (if available); Shift and a cursor key will lay a ‘non-bridge’ marker. Pressing the return key followed by a cursor key will also lay a bridge in that direction.
You can mark an island as finished by pressing the space bar or by pressing the return key twice.
By pressing a number key, you can jump to the nearest island with that number. Letters ‘a’, ..., ‘f’ count as 10, ..., 15 and ‘0’ as 16.
Violations of the puzzle rules will be marked in red:
(All the actions described below are also available.)
These parameters are available from the ‘Custom...’ option on the ‘Type’ menu.
High expansion factors usually mean easier puzzles with fewer possible islands; low expansion factors can create lots of tightly-packed islands.
These actions are all available from the ‘Game’ menu and via keyboard shortcuts, in addition to any game-specific actions.
(On Mac OS X, to conform with local user interface standards, these actions are situated on the ‘File’ and ‘Edit’ menus instead.)
The Load and Save operations preserve your entire game history (so you can save, reload, and still Undo and Redo things you had done before saving).
Some games (such as Solo) are capable of solving a game ID you have typed in from elsewhere. Other games (such as Rectangles) cannot solve a game ID they didn't invent themself, but when they did invent the game ID they know what the solution is already. Still other games (Pattern) can solve some external game IDs, but only if they aren't too difficult.
The ‘Solve’ command adds the solved state to the end of the undo chain for the puzzle. In other words, if you want to go back to solving it yourself after seeing the answer, you can just press Undo.
There are two ways to save a game specification out of a puzzle and recreate it later, or recreate it in somebody else's copy of the same puzzle.
The ‘Specific’ and ‘Random Seed’ options from the ‘Game’ menu (or the ‘File’ menu, on Mac OS X) each show a piece of text (a ‘game ID’) which is sufficient to reconstruct precisely the same game at a later date.
You can enter either of these pieces of text back into the program (via the same ‘Specific’ or ‘Random Seed’ menu options) at a later point, and it will recreate the same game. You can also use either one as a command line argument (on Windows or Unix); see below for more detail.
The difference between the two forms is that a descriptive game ID is a literal description of the initial state of the game, whereas a random seed is just a piece of arbitrary text which was provided as input to the random number generator used to create the puzzle. This means that:
(Use the ‘About’ menu option to find out the version number of the program. Programs with the same version number running on different platforms should still be random-seed compatible.)
A descriptive game ID starts with a piece of text which encodes the parameters of the current game (such as grid size). Then there is a colon, and after that is the description of the game's initial state. A random seed starts with a similar string of parameters, but then it contains a hash sign followed by arbitrary data.
If you enter a descriptive game ID, the program will not be able to show you the random seed which generated it, since it wasn't generated from a random seed. If you enter a random seed, however, the program will be able to show you the descriptive game ID derived from that random seed.
Note that the game parameter strings are not always identical between the two forms. For some games, there will be parameter data provided with the random seed which is not included in the descriptive game ID. This is because that parameter information is only relevant when generating puzzle grids, and is not important when playing them. Thus, for example, the difficulty level in Solo (sgt-solo(6)) is not mentioned in the descriptive game ID.
These additional parameters are also not set permanently if you type in a game ID. For example, suppose you have Solo set to ‘Advanced’ difficulty level, and then a friend wants your help with a ‘Trivial’ puzzle; so the friend reads out a random seed specifying ‘Trivial’ difficulty, and you type it in. The program will generate you the same ‘Trivial’ grid which your friend was having trouble with, but once you have finished playing it, when you ask for a new game it will automatically go back to the ‘Advanced’ difficulty which it was previously set on.
The ‘Type’ menu, if present, may contain a list of preset game settings. Selecting one of these will start a new random game with the parameters specified.
The ‘Type’ menu may also contain a ‘Custom’ option which allows you to fine-tune game parameters. The parameters available are specific to each game and are described in the following sections.
(This section does not apply to the Mac OS X version.)
The games in this collection deliberately do not ever save information on to the computer they run on: they have no high score tables and no saved preferences. (This is because I expect at least some people to play them at work, and those people will probably appreciate leaving as little evidence as possible!)
However, if you do want to arrange for one of these games to default to a particular set of parameters, you can specify them on the command line.
The easiest way to do this is to set up the parameters you want using the ‘Type’ menu (see above), and then to select ‘Random Seed’ from the ‘Game’ or ‘File’ menu (see above). The text in the ‘Game ID’ box will be composed of two parts, separated by a hash. The first of these parts represents the game parameters (the size of the playing area, for example, and anything else you set using the ‘Type’ menu).
If you run the game with just that parameter text on the command line, it will start up with the settings you specified.
For example: if you run Cube (see sgt-cube(6)), select ‘Octahedron’ from the ‘Type’ menu, and then go to the game ID selection, you will see a string of the form ‘o2x2#338686542711620’. Take only the part before the hash (‘o2x2’), and start Cube with that text on the command line: ‘sgt-cube o2x2’.
If you copy the entire game ID on to the command line, the game will start up in the specific game that was described. This is occasionally a more convenient way to start a particular game ID than by pasting it into the game ID selection box.
(You could also retrieve the encoded game parameters using the ‘Specific’ menu option instead of ‘Random Seed’, but if you do then some options, such as the difficulty level in Solo, will be missing. See above for more details on this.)
(This section only applies to the Unix port.)
In addition to being able to specify game parameters on the command line (see above), there are various other options:
If game parameters are specified on the command-line, they will be used to generate the game IDs; otherwise a default set of parameters will be used.
The most common use of this option is in conjunction with --print, in which case its behaviour is slightly different; see below.
On each page of puzzles, there will be w across and h down. If there are more puzzles than w×h, more than one page will be printed.
If --generate has also been specified, the invented game IDs will be used to generate the printed output. Otherwise, a list of game IDs is expected on standard input (which can be descriptive or random seeds; see above), in the same format produced by --generate.
For example:
sgt-net --generate 12 --print 2x3 7x7w | lpr
will generate two pages of printed Net puzzles (each of which will have a 7×7 wrapping grid), and pipe the output to the lpr command, which on many systems will send them to an actual printer.
There are various other options which affect printing; see below.
If --generate has also been specified, the invented game IDs will be used to generate the printed output. Otherwise, a list of game IDs is expected on standard input (which can be descriptive or random seeds; see above), in the same format produced by --generate.
For example:
sgt-net --generate 12 --save game --save-suffix .sav
will generate twelve Net saved-game files with the names game0.sav to game11.sav.
The following options are only meaningful if --print is also specified:
Full documentation in /usr/share/doc/sgt-puzzles/puzzles.txt.gz.