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Say you have a set of points and joining lines as show below:

t junctions are at D, F, and E

In this diagram of triangles, T-(or Y-like) junctions are at D, F, and E.

At vertex F for example, there is a triangle FDE, but no line FJ. If there was a line FJ, then there would be no T junction at F. Two triangles would be formed instead out of triangle-ACJ as tri-AFC and tri-FCJ.

How do you find the vertices that form "T" (or Y-like) junctions?

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I don't know much on this, but you would like to read this:… – anonymous Sep 5 '10 at 19:19
This on the other hand would probably have to be treated as a graph theory problem. – J. M. Sep 5 '10 at 22:15
up vote 0 down vote accepted

My first stab at it is to consider each triangle in the diagram, as well as all its adjacent triangles.

Consider tri-FEC first. FEC is adjacent to ACJ, but only one vertex is shared (C). If there is to be no T-junction, then two vertices should have been shared between adjacent triangles.

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