This is my entry for the Intel Threading Challenge, Phase 2, Problem 2, Amateur Level.

Pre-requisites

• Threading Building Blocks (TBB). Tested with 3.0, may work(?) with earlier versions.
• g++. Tested with 4.2.1 on OS X and 4.4.1 on Linux. Should work with other versions too.

To build it

• Make sure the environment variables for 64-bit TBB are set up (e.g. by running the tbbvars.sh script that ships with TBB).
• Run make

That should be it. The executable it generates is called 'hailstone'. It compiles cleanly on the OS X (Snow Leopard, 64-bit) and Linux (Ubuntu 9.10, 64-bit) machines that I've tested.

To run it

./hailstone

(as in the problem description).

The output includes the time taken to calculate all the sequence lengths for the range (excluding printing them out at the end), using TBB's tick_count class.