You should check out the Churchill Challenge (http://churchillnavigation.com/challenge/ http://churchillnavigation.com/challenge/) and the 54 solutions (source

You should check out the Churchill Challenge (http://churchillnavigation.com/challenge/ http://churchillnavigation.com/challenge/) and the 54 solutions (source code available at https://github.com/churchillnavigation/challenge1 https://github.com/churchillnavigation/challenge1). I came in at #7. Beyond the classic spatial search data structures, the fastest solutions all used SSE instructions (see https://github.com/sDessens/churchill-challange https://github.com/sDessens/churchill-challange for nice writeup). People did try pretty hard to win the grand prize of $5000, and the fastest solution was 7 times faster than the best optimized code that Churchill's team had previously.