You have two grids. Clear grid 2. Go over grid 1, calculate the new state for the current cell, write it to the second grid. At the end of a step you swap the grids.
Just slap on a good old "#pragma omp parallel for" with OpenMP (a nice guide is here [0]).
Just slap on a good old "#pragma omp parallel for" with OpenMP (a nice guide is here [0]).
[0] https://bisqwit.iki.fi/story/howto/openmp/
I also found this pdf if you are interested. http://www.shodor.org/media/content/petascale/materials/UPMo...