Here's the list of problems used in ACM Turing programming contest. Surprisingly, like many other such contests, lots of problems are s simply a variant of shortest-path problem. The ACM ICPC Problem Set Archive
This is the place to jot down relatively half baked impulsive thoughts in short text blogs. I call it "On The Run" version of my main blog at http://www.ShitalShah.com/blog which is where you'd rather be!