16 types of programming context problems in the USACO

Hal Burch conducted an analysis over spring break of 1999 and made an amazing discovery: there are only 16 types of programming contest problems! Furthermore, the top several comprise almost 80% of the problems seen at the IOI. Here they are:

• Dynamic Programming
• Greedy
• Complete Search
• Flood Fill
• Shortest Path
• Recursive Search Techniques
• Minimum Spanning Tree
• Knapsack
• Computational Geometry
• Network Flow
• Eulerian Path
• Two-Dimensional Convex Hull
• BigNums
• Heuristic Search
• Approximate Search
• Ad Hoc Problems

The most challenging problems are Combination Problems which involve a loop (combinations, subsets, etc.) around one of the above algorithms - or even a loop of one algorithm with another inside it. These seem extraordinarily tricky to get right, even though conceptually they are ``obvious''.

If you can master solving just 40% of these problem types, you can almost guarantee a silver medal at the IOI. Mastering 80% moves you into the gold range almost for sure. Of course, `mastery' is a tough nut to crack! We'll be supplying a plethora of problems so that you can hone your skills in the quest for international fame