Provided by: sgt-puzzles_9411-1_i386 bug


       bridges - topological deduction game


       bridges  [--generate  n]  [--print  wxh  [--with-solutions] [--scale n]
       [--colour]] [game-parameters|game-ID|random-seed]

       bridges --version


       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:

       +o      Bridges run horizontally or vertically.

       +o      The number of bridges terminating at any island is equal to  the
              number written in that island.

       +o      Two  bridges  may  run in parallel between the same two islands,
              but no more than two may do so.

       +o      No bridge crosses another bridge.

       +o      All the islands are connected together.

       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

       Bridges was contributed to this collection by James Harvey.

Bridges controls

       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. Pressing the
       return key followed by a cursor key will lay a bridge in that direction
       (if  available);  pressing  the space bar followed by a cursor key will
       lay a 'non-bridge' marker.

       You can mark an island as finished by pressing the return key twice.

       Violations of the puzzle rules will be marked in red:

       +o      An island with too many bridges will be highlighted in red.

       +o      An island with too few bridges will be highlighted in red if  it
              is  definitely an error (as opposed to merely not being finished
              yet): if adding enough bridges would  involve  having  to  cross
              another  bridge  or remove a non-bridge marker, or if the island
              has been highlighted as complete.

       +o      A group of islands and bridges may be highlighted in red  if  it
              is  a  closed  subset of the puzzle with no way to connect it to
              the rest of the islands. For example, if  you  directly  connect
              two  1s  together  with  a  bridge and they are not the only two
              islands on the grid, they will light up  red  to  indicate  that
              such a group cannot be contained in any valid solution.

       +o      If  you have selected the (non-default) option to disallow loops
              in the solution, a group of bridges which forms a loop  will  be

       (All the actions described below are also available.)

Bridges parameters

       These  parameters  are  available  from  the  'Custom...' option on the
       'Type' menu.

       Width, Height
              Size of grid in squares.

              Difficulty level of puzzle.

       Allow loops
              This is set by default. If cleared, puzzles will be generated in
              such a way that they are always soluble without creating a loop,
              and solutions which do involve a loop will be disallowed.

       Max. bridges per direction
              Maximum number of  bridges  in  any  particular  direction.  The
              default  is  2,  but you can change it to 1, 3 or 4. In general,
              fewer is easier.

       %age of island squares
              Gives a rough percentage of islands the generator will  try  and
              lay before finishing the puzzle. Certain layouts will not manage
              to lay enough islands; this is an upper bound.

       Expansion factor (%age)
              The grid generator works by picking an existing island at random
              (after  first  creating  an  initial  island somewhere). It then
              decides on a direction (at random), and then works out  how  far
              it  could  extend before creating another island. This parameter
              determines how likely it is to extend as far as it  can,  rather
              than choosing somewhere closer.

       High  expansion factors usually mean easier puzzles with fewer possible
       islands; low  expansion  factors  can  create  lots  of  tightly-packed

Common actions

       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.)

       New game ('N', Ctrl+'N')
              Starts a new game, with a random initial state.

       Restart game
              Resets  the  current  game  to  its  initial state. (This can be

       Load   Loads a saved game from a file on disk.

       Save   Saves the current state of your game to a file on disk.

              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).

       Print  Where supported (currently only on Windows), brings up a  dialog
              allowing  you  to  print an arbitrary number of puzzles randomly
              generated from the current parameters, optionally including  the
              current  puzzle. (Only for puzzles which make sense to print, of
              course  -  it's  hard  to  think   of   a   sensible   printable
              representation of Fifteen!)

       Undo ('U', Ctrl+'Z', Ctrl+'_')
              Undoes  a  single move. (You can undo moves back to the start of
              the session.)

       Redo ('R', Ctrl+'R')
              Redoes a previously undone move.

       Copy   Copies the current state of your game to the clipboard  in  text
              format,  so that you can paste it into (say) an e-mail client or
              a web message board if you're discussing the game  with  someone
              else. (Not all games support this feature.)

       Solve  Transforms  the puzzle instantly into its solved state. For some
              games (Cube) this feature is not supported at all because it  is
              of  no  particular  use.  For other games (such as Pattern), the
              solved state can be used to give you information, if  you  can't
              see  how  a  solution can exist at all or you want to know where
              you made a mistake. For still other  games  (such  as  Sixteen),
              automatic  solution  tells  you  nothing about how to get to the
              solution, but it does provide a useful way to get there  quickly
              so   that   you   can   experiment   with  set-piece  moves  and

              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

       Quit ('Q', Ctrl+'Q')
              Closes the application entirely.

Specifying games with the game ID

       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

       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:

       +o      Descriptive game IDs tend to be longer in many puzzles (although
              some,   such   as   Cube   (cube(6)),   only   need  very  short
              descriptions). So a random seed is often a quicker way  to  note
              down  the  puzzle  you're  currently  playing,  or to tell it to
              somebody else so they can play the same one as you.

       +o      Any text at all  is  a  valid  random  seed.  The  automatically
              generated  ones are fifteen-digit numbers, but anything will do;
              you can type in your full name, or a word you just made up,  and
              a  valid  puzzle  will be generated from it. This provides a way
              for two or more people to race to complete the same puzzle:  you
              think  of  a random seed, then everybody types it in at the same
              time, and nobody  has  an  advantage  due  to  having  seen  the
              generated puzzle before anybody else.

       +o      It is often possible to convert puzzles from other sources (such
              as 'nonograms' or 'sudoku'  from  newspapers)  into  descriptive
              game IDs suitable for use with these programs.

       +o      Random  seeds  are  not guaranteed to produce the same result if
              you use them with a different version  of  the  puzzle  program.
              This  is  because  the  generation  algorithm  might  have  been
              improved or modified in later versions of  the  code,  and  will
              therefore  produce  a  different  result  when  given  the  same
              sequence of random numbers. Use a descriptive  game  ID  if  you
              aren't  sure  that  it  will  be used on the same version of the
              program as yours.

              (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 (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

       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.

Specifying game parameters on the command line

       (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

       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 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:
       '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.)

Unix command-line options

       (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:


       --load These  options  respectively  determine whether the command-line
              argument is treated as specifying game parameters or a save file
              to  load.  Only  one  should  be  specified. If neither of these
              options is specified, a guess is made based on the format of the

       --generate n
              If   this  option  is  specified,  instead  of  a  puzzle  being
              displayed, a number of descriptive game IDs will be invented and
              printed on standard output. This is useful for gaining access to
              the game generation algorithms  without  necessarily  using  the

              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

       --print wxh
              If   this  option  is  specified,  instead  of  a  puzzle  being
              displayed, a printed representation  of  one  or  more  unsolved
              puzzles is sent to standard output, in PostScript format.

              On  each  page of puzzles, there will be w across and h down. If
              there are more puzzles than wxh, more  than  one  page  will  be

              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:

              net --generate 12 --print 2x3 7x7w | lpr

              will  generate  two  pages of printed Net puzzles (each of which
              will have a 7x7 wrapping grid), and pipe the output to  the  lpr
              command,  which  on  many  systems  will  send them to an actual

              There are various  other  options  which  affect  printing;  see

       --save file-prefix [ --save-suffix file-suffix ]
              If   this  option  is  specified,  instead  of  a  puzzle  being
              displayed, saved-game files for one or more unsolved puzzles are
              written  to  files  constructed  from the supplied prefix and/or

              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:

              net --generate 12 --save game --save-suffix .sav

              will  generate  twelve  Net  saved-game  files  with  the  names
              game0.sav to game11.sav.

              Prints version information about the game, and then quits.

       The following options are only meaningful if --print is also specified:

              The  set  of pages filled with unsolved puzzles will be followed
              by the solutions to those puzzles.

       --scale n
              Adjusts how big each puzzle is when printed. Larger numbers make
              puzzles bigger; the default is 1.0.

              Puzzles  will  be  printed  in  colour, rather than in black and
              white (if supported by the puzzle).


       Full documentation in /usr/share/doc/sgt-puzzles/puzzles.txt.gz.