[thelucky41]

This programming problem was what actually got me interested in compilers in the first place.

When I was 16 and learning how to program in Java, there was an online competition for high schoolers, and this was one of the introductory programming questions. Your program had to execute in under a time limit (5 seconds, N=13), and I had come up with the best solution I could and was still at 7 seconds. It took me the rest of the month spending hours a day reading on speed optimizations in order to cut down every unnecessary instruction, and remove every intermediate variable. Eventually, the program executed in 4.9 seconds.

While quite interesting, the problem only took an afternoon to implement the algorithm. What differentiated my chops from my competitors was that I could improve my program beyond the first implementation.