Pegraph for the iPhone and iPod Touch


Pegraph is a combination of sliding-block and planar-graph puzzles.

Pegraph has been compiled to run under iPhone OS 2.1 and will run under later versions of the OS.

Pegraph is available from the Apple iPhone App Store.

A Windows simulation of Pegraph for the iPhone can be downloaded (0.5Mb).

Pegraph is copyright © Peter Balch 2009

Some of the tiles have pegs and lines connect some of the pegs. Your aim is to move the blocks around until none of the lines cross and no line runs through a peg.

Lines that are crossing are shown in red and so are bad pegs. Good lines and good pegs are blue. Turn all the lines and pegs blue.

The resulting set of lines is called a "planar graph".

There are other planar graph puzzles available, so why make a new one? Planar graph puzzles are easy to solve. Once you''ve worked out the method, it becomes a mechanical chore. Making it into a sliding-block puzzle means that you must think much harder, even for very simple graphs.

You can search the internet for other planar graph puzzles including: Planarity created by John Tantalo; gPlanarity and Caboodle for the GNOME desktop; Untangle by Chris Benjaminsen. Pearl puzzles are based on cubic planar graphs.

Different Levels of difficulty are available.

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