Introduction to Graph Theory: Finding The Shortest Path (Part 2)

Why not Topcoder[1][2] tutorials? They are very inclusive, comprehensive and are not written in Ruby.<p>[1]: <a href="http://community.topcoder.com/tc?module=Static&#38;d1=tutorials&#38;d2=graphsDataStrucs2" rel="nofollow">http://community.topcoder.com/tc?module=Static&#38;d1=tutori...</a> [2]: <a href="http://community.topcoder.com/tc?module=Static&#38;d1=tutorials&#38;d2=graphsDataStrucs3" rel="nofollow">http://community.topcoder.com/tc?module=Static&#38;d1=tutori...</a>

Why would you call a Grid a Graph? A Graph consists of vertices and edges.<p>That doesn't seem reasonable for something like "Introduction to Graph Theory".